I own a CS-2, it's got some noise (the more you dial up the Sustain knob) but the attack knob and its envelope is quite musical. It kinda adds a nice high end boost to your tone and makes your attack on the strings more prominent. (VCA Compressor)
Tried my friend's Pigtronix Philosopher's Tone on bass and it was great! I'm guessing the Philosopher Bass Comp respects your low end more(?) but i was too busy being blown away by the
Oomph sound i could get from it to notice. Great for that type of slow but steady basslines, or even hiphop. I even thought a drumkick's signal would sound great with it. (Optical Compressor)
OP, i think i'd suggest you
this one for the one type of comp you're looking for! (probably better check the Philosopher Bass instead of the Philosopher's Tone, tho

)
Today i finally got to try a friend's Xotic SP Compressor. The low attack setting is too fast for my type of playing. Might be great for slap or fast Pastorius-like finger playing. The slower attack setting is more like it, kinda similar to the Pigtronix's attack but far more transparent. The HI comp setting is very extreme, but the other two (MID and LO) are quite cool.
This one also adds some high end to your tone, making the steel of the strings more noticeable imo. It has a switch to roll off the highs a little bit either way. (OTA Compressor)
Sorry for the long post, but i believe compressors to be one of the hardest pedals to know just from demos online. It's easier to me when people describe their experiences with it.