Does a receiver with more watts really make a huge difference? I am going to run 2 polk r40 floorstanding mains off the receiver with surrounds and a center channel and a sub with a plate amp. My receiver now has 80w to both mains channels. Is it worth it to upgrade to 100 or 120 watts to each channel? My room is 10.6 by 12, and I don't listen to the music(10%HT) very loud. Thanks.