Just upgraded one of the computers here to Wheezy (currently Debian Testing).
The machine is an HP Proliant Microserver - 1.3GHz AMD Neo II processor, integrated graphics and 250G disk - so low power and low spec. I' ve added three more 250G hard disks.
Very impressed indeed by KDE 4.6 and the general speed of response of a desktop environment on a low spec system. No audio subsystem on the system - it's a server - so I can't speak for sound quality.
I say this every time round about now in the release cycle: the next release of Debian (due later this year sometime) will be excellent :)