For most of the music I enjoy listening to, the clarity and separation of sound in upsample mode can't be beat. The PLIIx will provide some variation and for the most part, is tolerable. Regarding 7.1, after reading some of the members discussion of it, and out of curosity, I retrieved an old Pioneer SP700D sound processing unit from retirement, with its remote that can tweak just about everything, and surprisingly, I have found a couple of environments that sound pretty good running through the 990. It took some tweaking to get it right (mainly lowering the levels as the 990 and 7700 really brought out the processing). The 990 seems to clean it up a bit and makes good use of the bass management as gonk mentioned. So, I have been very pleased with all the options I now have, but the upsample remains the first choice. The 990 is a great unit, and the 7700 brings it all together.