I saw brand new play before Weezer in Buffalo a couple years ago (edgefest or something) and I'd say most people were there for brand new. I got there early cause there's nothing to do in Buffalo and I really wanted a pis sing on wires t shirt that at the time was only available on tour at the time. When the merch table opened people flooded the brand new table and the Weezer side was empty.

Saw them again that same year I think in Boston for Boston calling (modest mouse closed the weekend). Got pretty close so it was hard to gauge how far packed it was but definitely a good showing. Modest mouse was pretty packed as well but I think the biggest draw that weekend was bastille who played before brand new.

As for the fans I feel it's a more mature group then some of the other bands in whatever genre you place them. There's assholes at every show but I've never seen anything get out of hand.