I can say that I have found there to be a difference in my experiences with variuos brands, some have better power and sound quality than others, ie, the Sony $400 avr I purchased had a stated output of 100W/ch yet it did not produce the same sound, ie. bass was next to non-existent, compared to the Denon I had purchased because it had better features. Both were 2004 products and the Denon was my venerable 1804, a midline avr. The lack of bass from the Sony I attributed to a weak amp section, whether that be from a lack of capacitors or weak P/S or both I don't know. The Sony might have been able to maintain the power to satisfy the FTC rating to achieve it's 100W rating but it certainly couldn't keep up to the Denon.
