I've been a bit of an AAS fan since Tassman - the cut-down version 1 that was included with Sonar, or maybe it was still CWPA? Anyway, when they offered a bit of a deal to upgrade to the full version I did. It was, at the time, a CPU pig. That improved over the span of the next four versions, with V4 being no worse that any of my other vst instruments. And then they killed it off. I still have it on my system, and will keep it until it stops working.
Along came Chromaphone, first release was a bit resource heavy, but V3 is only a little bit of a resource hog, quite manageable really, since I can't imagine having more than 2 or 3 instances, and more likely just 1.
It sounds great to my ears. And you can create a pretty wide range of sounds. In many ways it feels like the logical extension of Tassman, and while the feature set is not quite as extensive, there are more than enough toys to play with.
I have only purchased one of sound packs, and I found it to be really helpful not just for the sounds, but for ideas for creating my own sounds. With the current sale I am thinking about adding a couple more (Epicenters, and Octagon).
Anyway, I think it is a cool, quirky vst synthesizer, and well worth the price, even more so at half off. (I have no financial interest in AAS, in spite of my enthusiasm)