Thanks for the reading! As a general point of knowledge, I know Flac is supposed to be lossless and .mp3 is lossy. However, I thought that the import of comments earlier in this thread were saying that Amazon was packaging lossy files for playback at 16/44.1, in a way that at least confused the issue or at worst is actually deceptive.
In particular:
"Anyway, mp3 files (and aac, ogg/vorbis, etc.) all decode to 16/44.1 for playback. The difference is the bit rate. Amazon uses 256kbps vbr last I recall. Flac is 1411kbps after decompression.
"Mp3 throws out bits that are "perceptually inaudible" to reduce the bit rate and file size. Flac reduces the file size (and bit rate during transport) using reversable space compression (similar to a zip file) without irretrievably removing any original information.
Sorry for my lack of technical understanding, I appreciate your parsing this out for me. I will read what you sent.