My roommate has the Sonuus G2M (guitar version). I definitely wouldn't want to gig with it as it's pretty glitchy and doesn't give you the kind of latency you'd need to play in the pocket at all. To get any kind of usable tracking out of it, you really do have to disable the pitch bend on your synth and sequence the bends manually.
Still, he's useless on the ivories and the Sonuus was a really affordable way for him to use his guitar as a midi controller for his DAW sequencer. You can just go back over your performance, quantize it, and remove glitch notes. Definitely beats clicking and dragging on little grid squares and trying to read a piano sideways for him, and he's gotten pretty efficient at sequencing with it.
I tried it out on bass. It didn't work at all, but if the guitar version is any indication of what this will be like, it'll be really useful for non-keyboard-playing bassists who want to record synths but I highly doubt it will be a live performance solution.