I consider this to be one of my favorite synths. It's not going to rival a $200 synth that can do it all (what would you expect for seventeen bucks?!), but what it does, it does very well. Everything about it is high-quality. I find myself using it all the time.
User Interface: This is a perfect example of how to make an elegant GUI that's also very functional and easy to operate. Like the dashboard of a BMW, all the controls are well-placed and it just plain looks good.
Sound: Gated sounds and arpeggios are what Feldspar does best. This is not to say that it can't do anything more--far from it--but the "tempo-based modulations" are stellar and really set this synth apart. The sound is invariably warm and rich.
Features: Although it probably isn't going to be the only VA synth you'll ever need, Feldspar can produce all kinds of sounds for those willing to learn how to use it. There are far more features than there appears to be at first glance.
Documentation: The User's Guide, in .pdf format, is very well-written, with precise descriptions of each control and how to operate it.
Presets: All the supplied presets are very good and useful, and there are many banks available for download on the Web site.
Customer Support: The developer is quick to respond and very helpful.
Value For Money: Feldspar is very well worth the small amount that is asked for it. It would be a bargain at twice that cost.
Stability: This VSTi has never crashed on me, and behaves predictably.
Take the money that you were going to spend buying dessert tonight and buy this synth. You'll be glad you did.