It's fairly capable, rather easy to use and sounds great. The user interface is rather intuitive, once you mess around with it for a bit you can put down the manual. I wanted something to play samples off of, such as some mellotron tapes and what not and this makes it incredibly simple, it will record the samples for you with no trouble. It's great for bringing a variety of sounds to play live or at rehearsals without having to carry a laptop with you and it's certainly a lot more stable, not a single crash or error so far. Multiple velocity layers work great, no complaints on that side.
I would have appreciated a way an input for an expression pedal, as playing stuff like piano is rather hopeless without pedals, but perhaps a MIDI capable pedal could be put to use. Tiny inputs and outputs are a bit annoying, but given the size, I suppose it makes sense.