I've had a Sony STR-845 for about 2 years now. I've always been somewhat underwhelmed by it-- regardless of what variety of speakers I threw at it. Kinda hollow would best describe it. Seeing this HK AVR-520 for around $500 has got me thinking. Or maybe it's the holidays. Anyhow, do you think I would notice an appreciable upgrade in sound quality for movies and music? Or would I need to spend *more* money to get the noticable boost. I want to be blown away like I was expecting to be when I purchased it. Maybe my expectations were out of sync with what I was willing to spend. Appreciate any comments or insights.