Crothian said:In one case the PC is completely ineffective and that can be not fun. In the other case the PC is dramatically effective which is more often seen as fun. Not the same thing.
Well, if you're going to get rid of every rule which might result in a PC failing to achieve his desired result, then AoOs are pretty far down the list, but I can understand that you'd get to them eventually.
You seem to have missed the point, however: AoOs allow PCs to both succeed and fail. Like every other rule in the game.
If you want to play a game where the PCs always get to do exactly what they want to do, then AoOs aren't your problem: D&D isn't the game for you.