It's definitely a character compressor - it adds flavour to your channel. It can be made to be fairly clinical, but it's not crystal clear, nor is it meant to be.

Features - very simple on the front panel - two huge knobs for compression and speed - it really couldn't be any easier than that. You don't have to know what threshold attacks and releases etc do - if you want that level of control then use a different comp, basically. You simply twiddle those 2 knobs until your sound is what you want. There's a stereo button (works in mono if not lit), locut and air (go on...have a guess what they do!), VCA or opto (VCA being a little more severe than opto, and quicker), a "complex" button (more of which later) and a switch to get to the inside panel for more detailed controls.

Documentation - separate d/ls that are an excellent read - well recommended.

Presets - covers all the main bases - guitars, basses, vocals, drums etc - all good presets well programmed to work with the instruments.

Stability - rock solid.

VFM - free. And still competes with expensive commercial comps.

Sound. A character comp - not crystal clear (although can be made to be pretty subtle). It's one that you'd use if you like to impart a distinct flavour to your compressed channel - much closer to analogue comps than most VST dynamics FX out there. With the speed on quickest and on VCA it doesn't let any transients through at all - obviously not how you'd always set up a comp, but good to know it will tame those difficult signals - and with high compression and quick speed, you'll hear more obviously the character of the comp - warm and ever-so-slightly grainy.
The real bonuses are the locut and air buttons - with heavy compression you might get too much bass - locut chops it out nicely, and air adds a great sparkle to those lost high frequencies (which if you didn't know - good h/w comps often lose highs - so it's not a fault - it's the nature of compression) Air is great for bringing accoustic guitars back to life after compression, and using both locut and air definitely helps with drumtracks - it means you can compress more heavily than you naturally might without ruining the nature of the channel.
Inside the panel is the real detail - you can alter the frequencies of the locut and air filters, and many details of the compressor itself to quite drastically alter the nature of the compression - or you can just subtly tweak it to get into some fine perfectionist detail. Often you won't need it, but it makes it very well-spec'ed.

"Complex" - changes it into a dual compressor linked in series. Useful if you want to use it more for groups or even as a master comp - a more subtle compression for each module that lets you compress more heavily with less audible pumping you'd get with just one compressor at the same compression level.

Not a do-everything comp - great for most situations though, full of character and alot more flexible than it first looks.