it's a relatively smaller con (about 3000, give or take). when it comes to guests, this is the list of guests that came for the past few years: http://en.wikipedia.org/wiki/Anime_Vegas
(the guests are mainly from the american side of anime, but they do have the occasional japanese guest). you can get every guests autograph in about 4 hours, which is awesome! when it was at cashman center, the only place that was crowded was the hallways, but (from what i heard) alexis park was crowded all over.
personally, i'm not a fan of anime vegas nor am i a fan of some of the staff, but the people that go (or at least the older fans) are awesome. from my experience, there were too many "you lost the game" being shouted, too many hall bums, and the occasional smelly cosplayer. you also have to remember that it's usually 100+ degrees outside, so you need to drink plenty of water and wear appropriate cosplays, or your con experience will suck.