i love the sound of my DBX MC-6.
and i use it on almost every analog capture that comes in..
whether it is vocals, bass guitar, electric guitar, acoustic guitar, keys, percussion, drums, etc....
i don't have any settings that i use all the time..
i set it up different for every track, every time.
i set it until it sounds the way i want.
in other words, i use it for color, compression, limiting, gain structuring, EQ'ing, anything i need.
i have not found a software compression plug yet, that sounds the way it does.
i highly prefer analog compression to software compression.
that said, i use a LOT LOT LOT of software compression,
i just use it very sparingly.
sometimes i crush individual tracks with a WAVES L1, and that is probably my most highly used compressor.
sometimes, i put the L1 in line, and reduce the compression levels to the point where you can't even hear a difference....
unless you really listen.
and that, to me, is about color.