Dude,
The 163s are great little units for the 40 or 50 bucks you get em for these days. I have often heard them referred to as the the Sm57 of the compressor world and I can attest to that vibe. They do a great job on almost anything in a pinch but sound great on kick, snare and bass guitar.
Operation could not be any easier.....ride the slider till you like the sound. I think everyone should have at least 2 of these things...you'll notice that most big studios even have a bunch around.
Cant go wrong...try one out!
heylow