I bought this piano to learn playing, so I can not tell a lot about sound and keyboard, but as for me they are really super, I would not tell the difference between acoustic piano and this one at my level.
Unfortunately the build quality which I can review relatively fair - has few flaws:
1. Stand is not stable enough. Even on flat surface, with prolonged bottom stabilizers (there is an option to add ~10cm to the depth of the stand) - it still shakes if not placed against the wall. I wanted to place it in front of panoramic window - so I had to put some soft pads between piano and glass so it has some fulcrum to not hang back.
2. The bigger problem appeared to be a defective plastic piece on a keyboard. Plastic panel on the right side of keyboard flipped out and stuck in a weird position - so I could not even open the lid (imagine my frustration after an hour of assembling : D). I did not want to wait for a return/replacement stuff - so I had to disassemble part of the keyboard and click the plastic part to the place. Fortunately it seems OK after that manipulation.