with only 37 keys, you can't play most of the more advanced repertoire. plus, this thing doesn't even have a weighted keyboard (piano keys are always weighted, even in an electronic piano), so it offers no piano touch at all. this thing is not meant for a piano player..it's meant for kids.
sound quality wise, synthesised piano sound is downright dead and dull no matter how good the technology might be, but i doubt any buyer of this keyboard would use it as a real piano. full stop.