Simply breathtaking sound! Previously, I had a very capable Sony STRDA50ES (100 x 5 of Sony power), then I got the 507 and some back surrounds...holy Toledo! The 'warm' sound that people here have used to describe B&K is pretty accurate, but the DETAIL in the sound is extraordinary. Not to mention having a TON of headroom (haven't even turned it up past -25 yet, will have some fun tomorrow though) This thing just sings, and really brings the system together in a way my good ol' Sony could not. The panning between speakers is just seamless, and the flexibility of the unit is astounding, yet I found the system setup to be really easy to work with (I didn't go into the really deep stuff with it yet). I wasn't sure what to expect as a level of improvement over my Sony, as I've never owned a piece of gear of this quality before. The difference is startling, not subtle, and DEFINITELY for the better. I'm extremely pleased! Even my wife could hear the difference and appreciate the quality! Lovin it to death, Dan PS Speakers are M&K all around; two pairs of SS150s, fronts are S125s, center is a S100B, sub is a MX150IITHX.