Have to play it to actually feel the ergonomics. I suspect the flip panel may not be very user friendly. It's not tilted enough - too vertical. If all the knobs are flat on the keyboard like the usual layout of controllers, it may be easier to play around with those knobs. Also, I hope the flip panel is sturdy enough. It appears to be hinged only at 2 places. Don't know whether the panel will shake when using the knobs, or whether the wear and tear will be a problem (causing the panel to fall off eventually).
I can see why the panel is on the left side - so ergonomically, the left hand can access the knobs. If the panel is extended throughout the keyboard, the right side of the panel will not be ergonomic since the knobs are usually only accessed with the left hand, causing a cross-over of hands during playing.
They call it the first "lap-top synthesizer"... Also notice that when the panel is closed, it makes a nice coffee table. Although you don't want to spill any coffee on it...
Another interesting feature - the grey strip above the keys is a 40cm ribbon controller! To bad it's only X-Y. If it's X-Y-Z, then it will be extremely cool!