It's hard to find reliable sources, but there's evidence that the difference between grass-fed and corn-fed beef goes beyond just having lower or higher fat content to things like fatty acids and conjugated linoleic acid. I don't know how much these things matters, if at all.
(Incidentally: I prefer to eat the beef of an animal that is free-range and grass-fed, then finished with some healthy corn feed without drugs.)
(Incidentally: I prefer to eat the beef of an animal that is free-range and grass-fed, then finished with some healthy corn feed without drugs.)