The Amazon's MP3 store is almost perfect.
The downloader works great on OSX.
The music is DRM free.
It's fast. (Faster than ITunes Music Store!)
Only downside so far is the lack of good recommendations. But I trust Amazon to fix that with a little time and data.
Bought 5 Albums so far.
Thank you Amazon for making an awesome Music Store. It's about time someone did it right.