He never used it vs Ay and bee.He hasn't used it much. Meaning he has used it in real combat. Meaning there's no "he can't use it in combat." The only debatable piece of information is how long it lasts.
He never used it vs Tobi
he never used it vs the kyuubi.
He never used it vs Juubito (only sage mode works on him yet he didn't use it)
Only time he used it was when he only had one arm and that was out of desperation. He cannot use it in a fight, that is all.