The editing of this effect couldn't be more basic. The device has two switches on it, one for Volume and one for Sustain. The good thing about it is that it has three different levels of attack (Fast, Medium, and Slow) that are controlled by a three-way switch underneath the knobs. The manual will explain all of these things in terms that make sense, but again, you'll need to experiment a little to know exactly what you are doing with it.
I used this particular compressor with my Strat in a Fender Twin amp. It's not a bad compressor for highly rhythmic, funky riffs, as it doesn't lose the biting sound that a clean funky electric will have. It prevents the ringing sibilants that can ruin a good scratchy rhythm. It's also not bad for ringing, open chords, as it will keep them sustained without robbing them of their glorious tone. I can't tell you how many compressors I've tried that have completely destroyed my clean tones. Now I get a healthy mix of sustain and tone when I'm strumming hard or letting chords ring. Unfortunately, this pedal is not perfect, as with heavier, distorted tones it's really almost useless. It doesn't give the kind of sustain that will really keep your leads soaring, and it's really noisy with distortion.
The only way to get the most out of this amp, in my perspective, is by using it in combination with another compressor. Preferably, the other compressor would have qualities that are completely different than this one, i.e. would sound great with distortion and not so much with clean tones. I'd have to say that for the price ($100), this is worth it if your guitar doesn't have a great natural sustain. Be forewarned though, that if you are used to playing clean tones straight through with no compression, this might not be for you.