I just got mine today. I'm impressed of the features, tweakability and most of all the sounds!
About the synthonizer: for me it would make more sense to have more control of the core sound itself than having the reverb (even though you can get cool Zawinul-sounds with the combination). The feature I miss most is control over the portamento, which seems to have fixed value (or is tweakable somehow?). Another option could be having only one attack-control for both A and B and use the extra knob for this purpose.