nandroid
just to report: backing up and restoring a nandroid works perfectly with pawitp's 0720 rom and sema jb. no loss of sdcard data as reported elsewhere.
i've tried making nandroids with slim bean stock, and that didn't work (but no loss of sdcard data at least). on both that setup and on derteufel's cm10 v4 and devil rc5 kernel, i was getting a line during backup saying it was "freeing up space", despite having 3500MB+ each time. derteufel's setup did make a nandroid, though.
so now, with pawitp's rom and sema jb, I made a nandroid and never got that "freeing up space" line. After that finished, on a whim i tried restoring derfeufel's setup. It completed, but gave me an error about looking for data.img. It rebooted to the Devil Kernel splash, so I was able to get back into Devil Recovery and re-restore it all.
from there, I flashed sema JB in heimdall, went into recovery, and got back to this pawitp/stratosk setup.
not the most efficient way to flip back and forth, but it was fun. saturdays are great, right?