I got this as part of the Waldorf Edition deal, so bear this in mind for the VFM comment.
How does it sound? Well, it's a filter. But also a distortion, delay, ring-modulator and bit-crusher.
Filter: This is the 'meat' of the thing. Sounds good AFAIC. Has LFO modulation and an envelope follower built in, so does wonders for drum loops. Resonance will go up to self oscillation, and I couldn't hear any stepping/ladders or whatever.
Distortion: In a word, brutal. Even on a very low setting, the volume has to be drastically reduced to avoid blowing the speakers. Vintage warmth this isn't, but if industrial sounds are your bag - look no further.
Ring Modulator: does exactly what it says on the knob...
Delay: Again, nothing particularly amazing, but usable.
Bit: Great and will actually reduce the sound down to nothing :)
interface is fine (looks like a waldorf should), midi CCs respond well, hasn't crashed yet. No support though, so that gets a fat zero. Presets are few, but it's so simple it doesn't really need any. Documentation is in the form of a proper book - pdf haters of the world unite!
overall, if you consider it as a freeby that came with the PPG and Attack, you can't really go wrong. If you consider it as a filter with two synths along for the ride, it still works out fine...