When you drive all 5 or 7 channels simultaneously, you won't be getting 100 watts per channel at any frequency anyway. Most of these companies never tell you the whole story. With all channels driven, you are probably getting 40 watts per channel.
Even the Onkyo receivers are rated with 2 channels driven, not all 7 channels driven simultaneously.
Even the mightly Denon 5808 is rated with 2 channels driven, not all 7 channels driven simultaneously. Although I'm sure it has plenty of power will 7 channels driven.
The only receiver company I know of that rates their receivers with all 7 channels driven simultaneously from 20 Hz - 20 kHz, < 0.07% THD is Harman Kardon.
So IMO, just look at the features vs price you want. Both of those Yamaha receivers will probably give you the same power.