I was in the exact same situation a while back. I've only had very limited exposure to the krc-hr from the dealer when it was 'new'. But from the reviews and memory it appreared to be the next step up from my 500i. But I ended up with 280p mostly due the to full 5 year warranty and I have a conscience (I am pretty loyal to the local dealer). I have no complaints or remorse with the 280p and I don't plan on replacing it. Can't say which is 'better' but for a krell system you can't go wrong with the 280p. FWIW,I can say: it is in every way better then the 250p.
Eric
Eric