No. As far as quality scans and general read back go right now, they seem to be equal (if I have paid close enough attention to the discussion surrounding them).
Just a note: Regardless of which LG burner wrote it (since no other manufacturer seems to have a drive out that supports M-Disc...at least that I've seen), there seems to be an odd quirk with some LiteOn drives where recognizing that an M-Disc has been inserted will take a while/won't work, or the quality scans will look uglier than from drives that have no issue with the media. Ignoring those quirks, though, things seem to be going moderately well. [I would love to find out if the quirk is on LiteOn's end, LG's end, is a result of the media itself, or a combination of things].