I don't always track with it. Like I don't have a need for it with my guitar synth or with a mic'ed electric guitar cab. If I want compression on electric, I'll use a stomp-box, but I seldom use one. Compression tends to sound lousy on classical guitar, so I don't use it there, plus there's just no need as classical guitars seem to have such an even sound without it. Steel string acoustic is hit and miss---depends on the guitar and how I'm playing it. I would tend to use it more on a dreadnaught for instance because they can be a little boomy. And with some steel string acoustics, compression really brings them to life, but I've had others where it didn't.
Also, DBX units all sound different to me. I don't think a 166 or 266 sound very much like a 160. I also had an old 163 decades ago and didn't think much of it. The 160 and its variants (I have the 160XT) was the great one in my opinion. I know there are compressors costing a few thousand bucks. I've never used anything in that league, so I don't know how they compare to something like a 160, but in the $500 and under range, I think the 160A or 160XT are hard to beat.
I also currently have cheapo Behringer Composer Pro-XL. It's a stereo compressor / limiter that I mostly use just once in a great while for limiting. It's not much of a compressor, but it's very quiet, and any limiter that's quiet and has a quick response time is fine with me. Limiting is easy---compression is hard.
Dang it. No world series game tonight....
Bill