- Windows Phone doesn't seem to respect ReplayGain. To be fair, I hadn't heard of ReplayGain when I bought the phone.
- Windows Phone corrupts MP3 metadata when it plays songs. The first hint will be that your phone itself will be confused about the artist and title. The next time you sync to your computer, Zune will flash a message about syncing something, and then your normal MP3 player (foobar2000) will start showing question marks instead of artist and title.
Metadata is not corrupted for all played songs. If I cared enough, I could backup my recently played songs before syncing and break out the hex editor to figure out why some songs aren't corrupted, and what the corruption looks like. Seems like a waste of time since I can't fix the underlying problem and don't really want to batch rebuild all the metadata in a form that WP likes.
The way forward seems to be keeping two copies of the songs. One for foobar2000, with good metadata, including ReplayGain annotations. The second with ReplayGain baked right into the audio, and therefor not really caring if metadata is corrupt.
I haven't found a single complaint that looks like this. Am I really the only one with one of these phones?