As I understand it, Soundstorm is the software that accompanies nVidia's
APU, which is present on their MCP-T south bridge (but not on the ordinary MCP). None of the boards in the above link use that south bridge.
As for its sound quality, I just finished playing a bit of Battlefield 1942 after installing a new motherboard with nVidia's APU, and the first thing I noticed was how much more alive the sound is compared to the Audigy LS I was using before. It's like everything suddenly got a lot more real. Of course, that was the first time I'd played after installing the 1.6 patch for Battlefield, so it might just be that the game patch included better sounds, but I doubt it.