I'm sorry? "there's not practical difference between 24fps and 60fps"?
Few people will be able to tell motion above 60fps, sure, but up to that point any human can and will notice the difference. Ever wondered why a movie's motion will look completely different that the motion of your standard news / soap opera / etc? That's the 24-to-30fps difference alone.
Adding features does not necessarily increase functionality -- it just makes the manuals thicker.