What is better-To say the blessing on one’s own or to be Yotzei with another/Chazan?
Mitzvos that are fulfilled individually: Whenever a Minyan of people are fulfilling the same Mitzvah at the same time, and each individual is performing their own Mitzvah, such as each person is wrapping himself in a Tallis or wearing Tefillin [or saying Sefiras Haomer] they can choose to either have one person say the blessing over the Mitzvah on all their behalf and then have each one perform the Mitzvah, or they want they can choose to have each person recite their own blessing. [There is no Halachic precedence for one way over the other, as each method contains an advantageous aspect.] The advantage of fulfilling the blessing through one person is “Berov Am Hadras Melech”, (while the advantage of saying their own individual blessing is to personally say the blessing rather than be Yotzei through a messenger, and thus increase in blessings.) [This advantage however of Berov Am is seemingly only applicable if there is a Minyan present, while if a Minyan is not present, it is better to say the blessing oneself rather than be Yotzei from another. Furthermore, the widespread custom today is for every individual to recite the blessing himself, even if a Minyan is present, and so is the proper directive. This however only applies to Mitzvos that are fulfilled individually, and not to collective Mitzvos.]
Mitzvos that are fulfilled collectively: Whenever a Mitzvah is being fulfilled together, collectively [with the same object], such as everyone is listening to the Shofar being blown, or Megillah being read, by one person, it is a Mitzvah for one person to say the blessing on all their behalf. Either the person blowing the Shofar or reading the Megillah is to say the blessing on everyone’s behalf, or one of the participants who are listening is to say the blessing on everyone’s behalf. The same applies if everyone is sitting in the same Sukkah, [that one person should say the blessing of Leishev Bassukah on everyone’s behalf]. The same applies for Kiddush or Havdala and all cases of the like [that it is best for one person to say Kiddush and Havdala on everyone else’s behalf]. Nonetheless, if every individual desires to fulfill the Mitzvah on their own and say the blessing on their own, they are permitted to do so. For example, if there isn’t a Minyan present and each person will read the Megillah on their own, or each person will blow the Shofar on their own, then it is permitted for each person to say their own blessing. Nonetheless, it is proper for one person to read for everyone else’s behalf in order to fulfill “Berov Am Hadras Melech.” This is not an obligation, although is preferable. [If they choose to perform the Mitzvah on their own, individually, then even if there is a Minyan present, there is no advantage to be Yotzei the blessing from one person rather than say it on their own, as explained in the previous case. If, however, there isn’t a Minyan present then it is preferable to say the blessing on their own rather than hear it from one person.]
Those Mitzvos that are performed individually, such as Tallis/Tefillin/Sefira, [it is better to say the blessing on one’s own than to hear it from another, unless a Minyan is present in which case] there is no preference whether one says the blessing individually or hears it from the Chazan. However, today it is better in all cases to recite the blessing individually, and so is the custom. However, those Mitzvos that can be performed collectively with the same object, such as a congregation hearing Shofar/Megillah/Kiddush/Havdala and sitting in the same Sukkah, then when the Mitzvah is performed collectively, which is preferable, it is a Mitzvah for the congregation to hear the blessing from one person. This applies even if a Minyan is not present. If however they decide to perform the Mitzvah individually, although this is not preferable, they may do so, and in such a case every person may say their own blessing [or choose to be Yotzei with one person, if a Minyan is present, while if a Minyan is not present, every person is to say the blessing on his own].
 Admur 213/6
 Admur 213/6; One interpretation of Tosefta Brachos 6/20; Or Zarua R”H 262; Mahram Merothnberg 7; Abudarham Seder Tefilos Shel Chol 3; So rule regarding Tzitzits: Admur 8/11; Michaber 8/5; Orchos Chaim Tzitzis 25; See M”A 213/7
Other rulings of Admur: Tzaruch Iyun from Admur 619/8 who states regarding the blessing of Shehechiyanu of Yom Kippur [and extends this as well towards Hallel and Birchas Lulav] that it is proper to be Yotzei with the Chazan due to Berov Am. Vetzaruch Iyun as to how this does not contradict the ruling of Admur 213/6 which states that by Mitzvos fulfilled individually [such as Lulav, and Hallel, Vetzaruch Iyun as to the definition of Birchas Shehechiyanu] one can choose whether to say it himself or be Yotzei with the Chazan, and there is no advantage either way. [See Hearos Ubiurim Ohalei Torah 805/72 who asks this question and suggests that Shehechiyanu is considered a collective Mitzvah, while the extension of Hallel and Birchas Lulav was never intended to be going on the beginning of this Halacha but rather on the second part that the congregation should finish before the Chazan. However see M”A 619/3 who does not learn this way]
Other opinions: Some Poskim record it is always a Mitzvah, in all cases for a group to prefer the fulfillment of a blessing through one person rather than through saying it individually, due to Berov Am. There is no difference mentioned as to the type of Mitzvos, or amount of people in the group. [M”B 213/3 and 17, based on Madneiy Yom Tov and Ramach; Implication of M”A 213/7 and M”A 619/3] Even by a Mitzvah that is performed individually, such as Tzitzis, it is preferable for a group to be Yotzei with one person due to Berov Am. [Implication of M”A 619/3 in name of Shelah regarding Hallel and Birchas Lulav and so can be implied from Admur 619/8; M”B 8/13 regarding Tzitzis, based on 298/14 regarding Havdalah, however Admur ibid explains that Havdala is a case of a collective Mitzvah and hence contains only the preference of Berov Am, while the Mitzvah of Tzitzis is an individual Mitzvah, and hence contains an advantage in saying the blessing personally.]
 Admur ibid in parentheses
The reason: (One is to always increase in necessary blessings, [and thus saying the blessing individually contains an advantage over being Yotzei with another, as it decreases in blessings]. Now, although one who hears is like one who answers [and thus there is no decrees in blessings] nevertheless, the one who blesses is the main blessing [i.e. the only blessing said], as he becomes an emissary for everyone to fulfill their obligation, and everyone fulfills the Mitzvah of the blessing through him. It is as if everyone is reciting a single blessing which is being expressed through the mouth of the person saying the blessing, as his mouth is like their mouth. Now, it is better for each individual to personally fulfill the Mitzvah of the blessing, rather than fulfill it through a messenger, as since every person is obligated in this blessing, this is considered an increase of necessary blessings, and is not similar at all to Chazaras Hashtaz, and Birchas Hazimun, as explained in 192/1, [as Chazaras Hashatz and Zimun is a collective Mitzvah on the congregation, and not an individual Mitzvah.]) [Admur ibid in parentheses]
 M”A 213/7 and Tosefta Brachos 6/20 “Ten people who are doing a Mitzvah together”, implying that less than ten does not contain Berov Am; Implication of Admur 489/1 who records this Tosefta/M”A and writes “As when there are ten Jews doing a Mitzvah together one Jew is Yachol/allowed to say the blessing on behalf of all the congregants, as explained in 8/11.” This implies that whenever there is less than a Minyan, then one is not initially to be Yotzei with another, as there is no advantage of Berov Am, and he loses the advantage of Mitzvah Bo Yoser Mibishlucho, and of increasing in necessary blessing; This can also be implied from Admur 8/11 and Michaber 8/5 who rules “If a few people are wearing the Tallis simultaneously, each one says their own blessing each person is to say the blessing on his own, although if they want, they can choose to have one person say the blessing, and the remainder will listen and answer Amen.”, now from the fact that Admur/Michaber plainly stated that each one should say the blessing on their own implies that it is preferable. [So learns M”B 8/13 in his initial inference] However, Tzaruch Iyun from the continuation of Admur 213/6 regarding the case that the Mitzvah can be performed collectively, who implies that even when a Minyan is not present it is better for them to perform the Mitzvah and blessing as a group, due to Berov Am, rather than as individuals. [Perhaps however there is a difference between that case where they are able to perform the Mitzvah collectively, and this case in which it is not possible, and hence only in this case does the individual blessing have the advantage of increasing in blessings, which overrides the advantage of Berov Am without a Minyan, while in the case there is no advantage of doing it individually, and it hence does not override the Berov Am of even less than a Minyan. In other words, the Mitzvah to increase in blessings is only when it is an individualized Mitzvah that cannot be performed collectively, or one is practically not doing so collectively for whatever reason. However, Tzaruch Iyun to create two levels of Berov Am, one without a Minyan and one with a Minyan; the latter being equal to the advantage of increasing in required blesisngs and the former being overriden by this Mitzvah.] Likewise, Tzaruch Iyun from the fact that in this very case here Admur does not stipulate that the advantage of choosing to be Yotzei with another’s blessing is only if there is a Minyan present, and if there isn’t a Minyan present then he is to say the blessing himself due to the Mitzvah to increase in blessings, and neither does he stipulate this explicitly in 8/11. See also coming footnotes. Perhaps then one can say that Admur in Hilchos Pesach 489/1 wrote according to the approach that Berov Am applies only with a Minyan while in Hilchos Tzitzis/Brachos [which he wrote later on] he decided like the approach that Berov Am applies by even less than a Minyan, and if so the final ruling follows the later codified law here in 213/6. Vetzaruch Iyun to create a contradiction in Admur if it is not inevitable, and thus the best thing according to all approaches, is simply to say the blessing oneself.
For different opinions on the definition of Berov Am-see: Ramach, brought in Kesef Mishneh Brachos 1/12, that less than three is not Berov Am; Biur Halacha 426/2 “Ela” in name of Chayeh Adsam 68/11 [three people is Berov Am]; Har Tzevi 1/19 [ten people as states Tosefta ibid]; See Sefer Nefesh Chayah 167/11; Piskeiy Teshuvos 213/2
 Admur 619/8 regarding Shehechiyanu, Birchas Hallel and Lulav “Although it is proper to be Yotzei with the Chazan due to Berov Am, nevertheless today …. every person should recite the blessing himself”; M”A 619/3; Chayeh Adam 5/17; M”B 8/13 that so is custom; Piskeiy Teshuvos 213/2
The reason: As in majority of instances the Chazan does not have in mind to be Motzi the congregation. Admur ibid; Chayeh Adam ibid; M”B ibid]
 See Piskeiy Teshuvos ibid footnote 9
The reason: As by collective Mitzvos, the same way the Chazan is certainly intending to fulfill the obligation of the congregation in his reading of Megillah or blowing Shofar, the same applies to the blessings that he recites.
 Admur 213/6; M”A 213/7; Mabit 1/180 in interpretation of Tosefta ibid; Admur 298/20 and Michaber 298/13 regarding Havdala candle; M”A 298/18
 The reason: As when a group fulfills a Mitzvah together they are considered like one entity/body and it suffices for them to recite one blessing. Accordingly, if every individual says their own blessing it is not considered a required blessing at all, as their Mitzvah is considered like the Mitzvah of a single entity, and there is not so much of an advantage of increasing in blessings. Now, although saying individual blessings in such a case is not prohibited due to a blessing in vain [Bracha Sheiyno Tzericha], being that every individual is obligated in this blessing, and even now through hearing it it is as if they are saying it [and therefore are Yotzei], nevertheless, since there is no advantage in the increased amount of blessings, therefore one person is to say the blessing on everyone’s behalf to fulfill the advantage of Berov Am. [Admur ibid regarding Birchas Hanehnin, and he applies the same rule to Birchas Hamitzvos of a collective Mitzvah]
 Admur ibid; Implication of Taz 585 brought in Shaareiy Tziyon 585/24; M”B 589/4 in name of Achronim
Other opinions: Some Poskim rule that initially the person who is blowing is always to say the blessing if he is currently also fulfilling his obligation. [Kaf Hachaim 589/12 and 585/38; Yoreh Deah P”M 1 M”Z 17; Piskeiy Teshuvos 585/9]
 The reason: One cannot obligate someone to fulfill a Mitzvah that is commanded upon him through an emissary, if he is able to fulfill it on his own. [Admur ibid] Vetzaruch Iyun why it is even preferable to fulfill the Mitzvah collectively, if we rule that Mitzvah Bo Yoser Mibishlucho, and seemingly one should be able to choose, without preference, which advantage he desires, just as we ruled in the previous case. However, in truth, the rule of Mitzvah Bo Yoser Mibeeshluchos does not apply in this case, as everyone is fulfilling the Mitzvah himself, as Shomeia Keoneh, it is just that they are doing so through the same object and voice, and hence there is no advantage of Mitzva Bo even if they say the Megillah/Kiddush themselves. Accordingly, one should prefer doing the Mitzvah collectively, even if a Minyan is not present. Now, once a Mitzvah is done collectively, it is a Mitzvah for one person to say the blessing on behalf of all, as Berov Am Hadras Melech, and there is no Mitzvah to increase in blessings, being they are considered like one entity, as stated in previous footnote.
 Whenever the group decides to perform the Mitzvah individually it has the same status as the previous case, of which we ruled that if a Minyan is present there is no preference to what they choose, as either option contains an advantage, while if a Minyan is not present then they should prefer to say the blessing individually. The only difference is that in this case we tell them initially to perform the Mitzvah collectively, and consequently have a Mitzvah to hear the blessing from one person, even if it is less than a Minyan. However, if they decide not to, then the same laws as the previous case becomes applicable.