SuperWave is one of those soft synths that has a distinctive sound. The UI is spectacular, of course, and the synth features are very well conceived, but what really makes this synth is the sound. Put simply, it is a great, great VA.
Loosely modeled after the Roland JP8000/8080, this synth comes with a great set of presets that do an excellent job of showing off its capabilities - and its full-bodied, warm sound. It's not a bread-and-butter VA sound like you might get in, say, a DreamStation, but it is highly usable and flexible.
I have had a few problems with the synth - stuck keys being the biggest, but the occasional crash also happens. Your mileage may vary.
Despite the fact that this synth was developed using SynthEdit, it really shines as a pro-level product. Why the developer gave it away free is a bit beyond me - but I'm glad he/she did.