What's "wrong" with the S1? Absolutely nothing!
I spent considerable time trying it out at Messe and I was floored by it. For my money, it's one of the best synths I've ever heard. It has a VERY broad sonic range -from bright, cold, cutting, clinical, and precise to dark, warm and fuzzy. The signal path is very clean and the pots have a very wide range. It is also very well made.
It has the reputation of sounding cold, but that's just if you don't know what you're doing. It has plenty of potential for funk and grit. The filter mixers can saturate, and Wowa Cwejman (the designer, very cool guy!) showed me tricks like feedbacking one mixer back into the other to push the whole thing into overdrive -giving you a distortion circuit with a tone control (because the filters are in the feedback loop). Lovely stuff.
It's a killer. I want one.