The Amazon MP3 album downloader thing is SO kludgy =( I think AMZN gets the broad strokes right but their details are just not top-shelf.
I bet they do end user support way better than Google, though.
As for the Kindle app for the PC, Mac, and iOS, love it.
Amazon is capable of producing high quality products, but they really need to be careful about letting crap be released. It can do irreversible damage to your brand.