Well said, Razmo, actually.
I think the first in a series is often the best and most unique. I find when I improvise, say, ten pieces in a row that, as I fine-tune my ideas and themes, a certain mystique or originality is lost. Afterwards, when I'm deciding which one to post, I always expect to prefer the later pieces, since these will have a deeper development of musical ideas that the early pieces lack. But most often, I surprisingly prefer the first one, which sounds a bit less organized but more spontaneous and inspired (pardon the vanity).
I think the same is true with Dave's line of instruments. The Evolvers came out of nowhere - sort of a burst of inspiration and originality - full of imperfections and quirks, but with nothing immediately comparable. As Dave progressed and refined his ideas, a degree of monotony set in. There was the Prophet 08/Mopho/Tetra era with one very similar instrument after another. Even I got bored with it all. Finally the Prophet 12 appeared, which was then followed quite predictably by the Pro 2. Both instruments were the products of the lessons learned on previous instruments and showed a maturing of concepts. Following these, the P6 was a drastic change, and yet, it really was a ghost from the past, an updated Prophet 5.
In the whole line-up, the Evolvers appear to me to be the most unique - and that's not to criticize the masterful P12 - and I guess this is why I have such a stubborn fondness for them. Sure, there's plenty wrong with them, especially the aliasing of the digital oscillators, but there's still a massive amount of musicality in the engine. I love the fact that the stereo signal is a matter of hardwired oscillators that can be adjusted by degrees. It's an excellent starting point that avoids the loss of an LFO. It's a fabulous instrument to sit with in a dimly lit music room and play into the wee hours. That's when you know an instrument suits and inspires you, when the time disappears as you work/play, and suddenly you look at the clock and it's 3:30 in the morning. I've had many-a-groggy morning, thanks to those Evolvers.
I've had a number of synthesizers over the years that I liked very much, but I couldn't call any of them unique. The Poly Evolver Keyboard is totally unique.