The ART Pro VLA II was my first piece of analog gear and I've been using it for pretty much everything: drums, vocals, bass, synths and even for catching some peaks on the master channel. It won't add any 'mojo' to your sound, but it's a great unit for those of you who are just getting into the world of hardware and want to learn about compression.
The building quality is very robust, the knobs comfortable to work with. It doesn't feel cheap at all.
It's not the most transparent compressor out there, but if you're looking for an affordable all-around unit that can add a little 'tube sound' and color, the ART Pro VLA II is the way to go.