Which takes us back to the original point,... looks like a waste of money

if you are looking for improved performance by down grading your speakers and up grading your receiver,.... probably not gonna hear a difference for the better, especially with MP3's. Not saying an upgrade is a total waste if he needs the HDMI or other features of a new receiver. I just think if he is expecting "musicality" or some other audio revelation in moving from an SR600 to an 805 he is going to be sorely disappointed.
I don't think anybody is disagreeing with you. Certainly not I. My only point was that all compressed files are not the equivalent of those sold on line by the music services. It is possible to have compressed files - even MP3 files - that sound close enough to the original that the differences are meaningless. The "sound" of a receiver should be about the same as any other receiver - in other words, there should be no sound other than that of the amplfied signal.