For me, I don't mind so much the scale itself in any form, although I do think an A, B, C, D, F works nicely as everyone knows what that means. But.
I think breaking up the score by category is infinitely more useful. Meaning a rating for Graphics, Gameplay, Sound, Replay, and Overall. Sure, it's more work, but it says a lot more.
Take a game like R-Type. It's very nice graphically and the sound is well suited to the game. Gameplay is solid if not very hard and that can be reflected in the Gameplay score. And a hard game may not have too much replay value for some people. Now I would appreciate that type of scoring breakdown. It helps people draw conclusions based more on what's important to them. Graphics whores are going to favor that category and those looking for the longterm satisfaction will more heavily rely on the replay mechanic.