it seems on the surface that the biggest difference is in the amp sections. They both have basically the same features with each having some advantages over the other. The 525 enjoys the new triple crossover and bass management from the analog inputs. and seven channels Of course it does lack THX (not a big deal to most) and logic 7 over 5.1 sources, which everyone seems to love. My wife surprised me by ordering the 8000 this weekend while I was at work. She got sick of me spending more time reading in the forums and shopping around online then spending time with her Im hoping for the best. I know that some 8000's may have issues, but the good ones are supposed to sound very impressive. Im keeping my fingers crossed.