First off I really want to VERY strongly recommend that you do not judge the sound of the pianos until you have downloaded some of the additional sounds from their webpages. Particularly the new Stage D.
My first impressions out of the box, were overall very good - except I found the pianos to be a bit dull and uninspiring. Serviceable, but not great.
However, the new pianos change this completely. Stage D is so much more dynamic, responsive and fun to play. It's very easy to add with the Numa Manager, and I really feel this is so much more complete as an instrument now.
The keybed feels great, and it's overall a nicely built quality instrument. Solid metal chassis, controls, buttons and knobs feel reliable. Operation and the UI is very simple and intuitive.
Sound wise, this isn't like your typical digital piano where you just hit a preset and expect the best to come out, it's more something where I immediately start sculpting my own presets (which is a good thing in my book). It rewards a little time invested. And when you have your own sounds setup how you like, you always have immediate control over the parameters and master EQ and insert FX. Very nice.
I am still just enjoying the e-pianos and pianos from the onboard engine, but I will soon be having fun with connecting my iPad to use all kinds of different music apps I have there. This adds a whole other dimension to what you can play around with since you can bring in anything as a layer or audio in.
Of course, nothing is ever perfect, and I do have minor criticism, some of these may or may not be important to you.
One, on the physical design, is that you have a power supply with a thin little cable. Not the best for stage situations, and this is a stage piano.
Two, there are imperfections on the recording of some samples when playing piano keys (and this applies to several of them). Eg. some you can hear a tiny crackle of digital overdrive on certain keys/velocity levels when playing with headphones, where you hear every such detail. Which is a little distracting to me. However, on speakers or in a mix this isn't going to be very easy to notice, and it doesn't really bother me much when the instrument is so good overall. But it is something that could probably have been fixed with eg. Izotope RX, so while the sound is overall great, I will knock off a point here.
On the audio interface part the lack of ASIO may be relevant to some.
Not actually a concern for me, for studio/recording I'll use MIDI for a plugin, or record audio from line. But something to be aware of.
Overall, I quite love it, so I'm happy with my choice. It's great value for all it offers, and it has a lot interesting functionality to play around with. Also for 88keys, the weight is very manageable with a nice bag.