Having had the Hydrasynth for a while now... I get continually blown away by it. The poly aftertouch is the best I've ever played on a "regular" keyboard, just SO sensitive and expressive. A big + is the aftertouch implementation, where you can set delay, fade in (attack) time and fade out (release), and sensitivity of course, for tweaking to fit any occasion. It brings new life to many old AT capable instruments, in my case the JV-2080, ASR-10 and Rev2.
One con(-) though... the keyboard lacks 'release velocity' capability, which surprised me. Not THAT big of a bummer, but release velocity would be nice. Apparently, they implemented it on the newer Hydras though, Explorer and Deluxe. While my JD-800 sends release velocity, it doesn't have poly AT, so...
Anyhow, the Mod Matrix is way too hard to keep track of on the Hydras screen, for me at least... so I've made an interface for the iPad app TBMS, to keep track of the Mod Matrix and Macro routings. I will post it here in a while.