If I have to choose between 2 HT receivers.

The 2 are 5.1 Onkyo with 75 wpc and the 7.1 Yamaha with 110 wpc.
Is it that the Onkyo is a better brand and sounds better in sound quality or is it that the Yamaha has more wpc and so the sound being better.
My primary requirement is a good sounding 2 Ch. Audio system 5.1 or 7.1 does not make a difference to me. Hope this is not too dumb a question.