Does BeRov 'Am Hadrath Melech (the King's glory is in the multitudes, ie., the more people praise HaShem together, the more glorious it is for Him) apply to making Kiddush? I've heard it said so somewhere, but I cannot remember where. I'm specifically interested in whether it is better to have one person making Kiddush at a large meal or having everyone make their own.
See Aruch HaShulchan 273:6 where he writes that there are those places where everyone makes his own kiddush, but "it is not appropriate to do so, and you should prevent them from doing this, and teach them that the mitzvah is better when one person makes kiddush on behalf of everyone." And he writes that the reason it is better is because of ברוב עם הדרת מלך
The Mogen Avraham Siman 193:2, Shulchan Aruch Horav 185:4, and Mishnah Berurah Siman 193:5 say that it's best if everyone says it with the leader because it's hard to be Mechavin and listen to the Mekadeish.