Hi Pale. Yes, the SB4001 is a VCA comp. I agree with you, after listening on the Clipalator I wasn't so sure about it. I just couldn't tell much from the demo. Yes, it shines on the two buss. It's not as fast as an FET, so it won't be my first choice for achieving dirty drums on a drum buss, but I have 1176's for that. (although it will get close) Havent tried it on bass yet, but vocals! Read TapeOp's recent review on it here: Tape Op Magazine > Reviews > SB4001 500-Series bus compressor
What they said about vocals is true. This thing kills for pure, clean vocal compression. I like to track vocals with some compression on the way in, but I don't want to be heavy handed with it. This gives me the volume automation I like to achieve on vocals on the way in. Makes mixing an easier task. Well, for me anyway. As always, YMMV.