Can anyone explain the differences in these models?
I have two Sound and Vision Buyer's Guides (2003 and 2004) and there doesn't seem to be much different in the models, other than:
AVR 430 7x65W
AVR 525 7x70W
AVR 630 7x75W
The AVR525 didn't have Dolby Pro, whereas the others do.

Is the older AVR-525 missing any new options, or are new models brought out just to increase sales?