Stephen,
Quick answer is that if you can get a KN7000, do so, overall it is a better keyboard. To put it in perspective, I obtained the PSR3000 only as a financial way out from investing in a Motif ES7, then discovered that it was way beyond my musical (and technical) competence to utilise effectively. Having said that, the PSR3000 is a very good keyboard though compared with the KN7000 sounds "tinny" with the onboard speakers. However when sent through my Behringer Truth monitors it is very good. The monitors bring out a fuller base note and also the subtleties such as cymbals and so on, which seem to get lost from the on-board speakers. However I play in a small home study, not the best for either instrument.
Keith