Since.this a thread about tracking compression, The key to any sound is to record it as close to the end result as possible, so if you want really ambient guitar don't play really heavy handed and close Mic it with the aim of fixing in the mix with a compressor because the end result won't be good at all.
Instead find a nice space with the right acoustics and distance Mic a well played even, light touch guitar. You can then enhance the sense of ambience with some fast light attack compression, Reverb, delay, LPF if the track even needs it.
If you want good guitar tone work on that rather than tracking compression.
IMO There's too much emphasis on gear which to a large part is pushed by gear makers and their endorsers. There's no doubt an 1176, LA2A, LA3A, some of the DBX stuff or even some cheaper stuff like the RNC or VLA etc, etc are really good at musical sounding compression but they don't do miracles in fixing performances or creating tone that did not exist in the recording.
All things come from the source material, everything after that is like adding seasoning to a steak, a little goes a long way. Just as you can't take a bunch of hamburger meat, squish it together, dump a ton of steak seasoning on it and expect it to be a filet mignon, You can't take poor or inappropriate source material dump tons of FX on it and expect it to sound like a record.