Good Drellisdee (and everyone else), I'm pleased to report that my Music Tab is working properly now. I've re-synced all my music (1200+ tracks, ~8GB) back onto the device, and I've only had playback stutter
one time, and that was in the middle of a track, not the old every couple seconds it was doing. I'll check that MP3.
All I did was reformat the SD card and re-sync. I used 4K blocks instead of the default 8K, but that shouldn't mean anything for files these size. I also noticed that the scan/album art step the Music Tab does took notably less time than it ever has.
Watching AudioManager_eng in task manager, I'm seeing a relatively even 2-5% CPU usage with no spikes every few seconds like it was doing to me before. It's still a beast of an application and drags the phone down, but it works!
I do know this post has little to do with the custom ROM, but I also know others have been having problems with music stuttering. I don't know why just cleaning off the SD card and putting everything back on it exactly the same way made such a difference, but it did. Might be something you other folks can try. I formatted the microSD with FAT32 and 4K blocks.
Hope this is useful info
EDIT: Oh wait -- I did one more thing on a hunch, and it may actually be important. Sorry I forgot about this in all my MP3 happiness ... I removed any MP3s with special characters in the title/artist. My guess there was maybe the HTC app was choking on them. In my case, that mean removing everything by Blue Oyster Cult and Motley Crue (don't judge) because I have them stored with the 'proper' umlauts in the names. My Roku Soundbridge chokes on those as well, so I thought it was worth a try. I'll put them back before I flash the Imagio next to see if that was relevant. I'm hoping to stick with it as-is for a while, though