Item quality and multiple players?

[Mavfin]

I would write that off as a rumor. Each person gets loot as if they were alone, and the only modifiers would be the averaged MF and GF of the group.

I've not heard or seen any evidence that multiplayer gives any better loot at all. I think it's one of those things where someone's seeing what they're looking for. Same as Demon Hunters notice Vortex every time it's on an elite pack, while Barbs don't really notice it.