Actually, I've only read it at the ProjectXbox site. I've also seen it on a couple of other sites. They could be way off for all I know, but like I said, it sounds pretty much the same as MP3 encoded at 128kb.
I just started ripping some of my CDs onto the HD for use as a Jukebox. So far, I am very pleased at the quality...pretty damn good for 128 Kb/sec bitrate. I would say pretty much identical to MP3 encoded at the same bitrate. I mean, it's not up to the level of my hi-fi transport, but then...