I personally don't like Zenith, as it's a fairly small place with no air ventilation. This caused me to faint during a concert (fortunately narrowly missed hitting my head on the metal bar behind me). OK, so I got to go backstage, but I wasn't exactly fully conscious to enjoy the experience of walking past Twiggy Ramirez. I saw A Perfect Circle and the Deftones. The sound quality wasn't great either, but I usually blame that on the good old technicians

However, if a band is playing there that you really like, then it's not like you're not gonna go

I wouldn't go back there on a whim though.