Last month I tried the new Amazon MP3 service but I found a bug that caused files to be delivered at 160kb compression instead of the advertised 256kb. A few days ago, Amazon contacted me saying that the bug was fixed and asking me to try again to download the same album, Anouar Brahem's Le Voyage de Sahar. I just went through the process, which was a bit messy because I had to download the .amz files for each track individually and then get the real tracks downloaded by the Amazon downloader. In addition, there was a bit of confusion between the old, 160kb copies and the new 256kb ones, but all is well now and I'm listening to another Brahem wonder.
Out of curiosity, I checked the iTunes store for this album. They have it, but with DRM at 128kb AAC, not their DRM-free, higher-quality iTunes Plus. What's with this? Between DRM-free 256kb MP3 and DRM-encumbered 128kb AAC, it's no contest. I prefer AAC other things being equal, but this is definitely not equal.