if prefer doing most upper body exercises on a sunday and then lower body on a wednesday, with tri's now but i seem to be getting good gains as it is

and don't training almost through all the week mean ALOT more intake of proteins, vitamins etc.? and some exercises involve working a different muscle group that you might have been training the day before, its still recovering therefore you may lose a tiny bit there.
i prefer working out for an hour myself as i can work more muscles and i still get mass, strength etc. without going through everyday thinking 'crap, guess im working out again' as it becomes more of a job training almost everyday