I've watched NFL games at a dozen other stadiums. I love the Bills game day experience but even i can admit, the language and poor behavior are the worst anywhere. I won't even get into what happened to a couple college buddies of mine (back in the 80's) when they wore opposing gear to the stadium (i warned them not to). Yes- there are tons of great people at RWS but a few just go overboard.
Also, i think people tend to be better behaved in Dome stadiums. It's something about being outside where you feel more liberated to drop F-bombs all over the place...as opposed to being in a warm, comfy, kind of quiet indoor stadium.