I've probably seen around 50 shows at the old and new 9:30 (most at the new) and I'd say it really depends on the music. The crowds are generally well behaved, but if the band is hard, there will be moshing, and on occasion people beat the crap out of each other (in the most loving way they can, of course). Luckily, there is always the back of the floor (which isn't a bad view) or the balcony ... so if you're being bothered, you always have a place to go.