I have to admit, when I first replied, I was thinking, it (the NAD), was a different model, the T753. I apologize as this makes the argument here pretty null.
With 5 channels driving on both receivers there would be liitle differece. With a 2 watt difference there would be no audible difference and a very small measurable one. To that argument I would concede. However, I was referencing the "all channels driven" power numbers, 7 for Yamaha, 5 for NAD, understandably it is not quite fair, but in that case the NAD would have more dynamic capability. While driving only two channels, the Yamaha would have a 2db overall output advantage, which would most likely be, for most people, inaudible. The NAD is rated at 70 watts x 2 cont. both channels driven at .08% thd in two channel mode. 50 watts x 5 cont. all channels driven simultaneously at .08% thd. Sorry guys, it was "one of those days."
I do have to say though, that I prefer a manufacturer that is totally honest. As to one that says, "because our receiver is capable of driving each channel to 120 watts x 2, it must be able to do it on all channels while using them all simultaneously", which is just not the case. If the receiver only does 48 watts when 5 channels are driven simultaneously, then say it. I do not care if they use the 120 watts to market the receiver but it should be stated otherwise somewhere in the manual.