As with all compressors, the Keely compressor smooths off the rough edges and adds sustain. The Keely provides transparent, clean and low-noise processing, albeit as with all compressors, it will have some noise when it is hunting for a signal to elongate, but quieter than most.
It is easy to dial-on your sound without being overly complicated. The dry signal can be blended in to have attack when you spank it; and then as the dry signal decays, we hear a smooth, compressed finish. There is also a tone control which opens up higher frequencies so as not to lose sparkle, bite and chime if desired. The gain can be adjusted upward to produce impressive overdrive.
It is an unintrusive compressor that you really don't realize is in the signal path, but you know when it's not.

Used to have an MXR dyna comp but it never really caught my ear. Decided to try this pedal to get a more crisp clean tone and some added sustain and WOW! It really does the trick. I'm not a big compressor guy so I don't know what makes it better than the dyna comp but it is.