thats very subjective...imo reciever power is reciever power, there is not going to be a huge difference, the speakers are what make the difference. however yamaha is probably the most rock solid avr company. 3yr warranty vs the pioneer 1yr. the 1522 is a 9.2 vs the a820 7.2. i would base my purchase on warranty, reliability, and features. 100watts vs 130watts is not going to make any difference. i do like how yamaha has the built in 7band peq so you can adjust the sound to you liking.