I'm guessing that if the average musician was blindfolded in a room and only one was played, he/she would be hard-pressed to say which one it was. BUT...in the video below, in the comments section, the majority seemed to favor the Casio PX560. Unfortunately, the Yamaha 515 was not included. To me, the Casio seemed a little 'heavy' (ponderous, thick, too full, don't know quite how to describe it) but definitely not 'bad', just probably not my first choice among those three. But as we always say, it's purely subjective, and all sounded really good (the Casio being 'killer' at it's price point). Of course, key feel can not be demonstrated in a Youtube video, so it IS important to go to the store and play one.

I'm still up in the air and spending lots of time (too much ) checking out Youtube demos and reading comments of all the models mentioned in this class of digital piano. Thanks for your input. Still loving the SEVEN but still trying to adjust to it's keyboard action. Not quite there yet.

https://www.youtube.com/watch?v=v-yO6caa1z0

chas