Owning both the PSR549 and the WK-1800 I would recommend the PSR for two reasons. First the psr sounds are a little more realistic and better. Second, with the psr you can play the split voice with the left hand while finguring the chords. This is nice forballads-pads and for layering sounds. The only problem I had was recording the left hand peyered voice overtop the autoaccompyment. The Casio has two good fetures too. 76 keys, and a notation window. The notation windowis great if you don't read music but would liketo learn.