CM is senjutsu. Could've break out some sage art jutsu(s). I don't know man. Either Orochimaru didn't fully train him or plot didn't want Sasuke to become Sinbad!
Ah, people other than me know this.
there have only been 2 real nerfs in the series. they where when naruto stopped wearing the epic sage cloak he wore when fighting pain, and when madara became juubi jin and had to put a shirt back on.

madara looked better with his shirt on u faq
Shonen Logic: When a character is forced to remove their shirt, whether through damage or other means, their power grows exponentially.