The best advise I got before buying a digital piano was to prioritise on the needs. If you're looking for a digital piano, than the first thing that should be on top of your list is the feel of the keys. Then durability and sound follows. The Kawai has a splendid keybed, only it's bigger brother the MP-11 SE is better (but is also way heavier which is not ideal if you want to use it on stage). I also checked out the Yamaha CP-88, the Roland RD-2000 and Korg Grandstage but in the end I have picked this one. Reason is straithforward: it has better keys. The Clavia Nord Grand stagepiano has also the keys from Kawai, but that one is almost 3 times the price of this Kawai (though it will offer better sounds).
Sound wise, it's always personnal. Ik my opinion the Kawai sounds more then decent. OK, it's perhaps not completely on par with the more expensive competitors with their build in piano engines... but... it depends what you want to use this paino for. On top, if I connect my PC and use the Kawai as a master keyboard, I have all the sounds that I can wish for and tweak as far as I want. There are plenty of virtual piano's out their that will give you the perfect sound that you need.
In short: the Kawai might not win any beauty competitions, but this one is extremely well build. If you ask me, price wise, this is the best quality you can get at this price point.