From what I've read of compressor pedal reviews, it seems like people use them mostly for cleaner tones.

And I'm thinking this is because distortion kind of compresses the sound on its own, right?

So my question is: do any metal or prog rock lead guitarists use compression along with their distortion/overdrive?

And if so, would it be best to get a compressor/sustainer combo pedal?

I notice the Carl Martins are supposed to be really good, but it doesn't look like it includes sustain.