First off, I highly prefer hardware over software. But I like this softsynth a lot. It's the one softsynth that's kept me up well into the night because it's so much fun to play with.
Gui: Very simple and easy to use. So simple that a manual is completely unnecessary.
Sound: Only 2 oscillators, but can deliver a fat, analog-type sound.
Features: The filter has a dual function; as a normal filter and as a vowel filter. This is the feature that most attracted me. The LFO, envelope generator and sequencer have graphical range controls with upper and lower limits; very straightforward in their useage. All can be triggered via 4 or 5 parameters. The LFO has a graphically-adjustable waveform generator. There's also a motion control that I haven't quite figured out yet. There are 2 effect banks with the standard effects (reverb, delay, chorus, etc.). Most controls are right-clickable for additional options.
Docs: Adequate, yet unnecessary for such a simple synth.
Presets: Comes with 200 presets that are categorized. A great starting point for tweaking.
Support: Haven't needed any support. It works just fine. I payed the $$$ and the serial number was immediately emailed, so I was able to use it within a couple of minutes.
VFM: Certainly reasonable from a Euro perspective, but with the USD to Euro exchange rate difference, it was a tough decision. Still, I think it was worth it.
Stability: No problems whatsoever. It runs fine in Cubase 3 on my 3.2gh PC with 2gb RAM. I assume that it will run fine on any PC over 5 years old.
This is the one softsynth that I wish was available as a hardware synth.