Written info on 'only redbook cd' players (eg.Bryston, Lyngdorf, Rotel (?)...probably others as well) implies that because the setup (laser? clock?) is only for the above, they would produce a better output than those which can read dvd data discs as well (eg.McIntosh MCT Transports). Not considering their on board dacs, just digital signal. True? False? Not noticeable difference? Simply a marketing line?