I have to admit I expected good things of this club - famous Rock club, owned by Johnny Depp, and in the end it was a classic LA experience - lots of hype, and the reality of it not that great.
The club has two floors - live band on the top floor and downstairs is a small chill-out room with comfy sofas and laid back music. Usual black and red decor of a rock club.
To be fair I'd say it all depends on what band is playing there. On the night I went the band was just a poor imitation of Tool with some crappy mixes in between sets. So I'd recommend checking out who's playing at the Viper Room before going.