I've had pretty good luck matching up files, but I agree that it's time-consuming and dicey, which is why I've been looking into four-tracks. If the dr2d allows two sets of external mics, that's a huge plus; I'd much rather have two stereo line inputs, though, at which point it looks like I'd need a Tascam DR-680, which is outside my price range at the moment.
Speaking of drift, though, I've introduced it to the topic. So anyway, about the M10...