Spoiler: show
Patamon going mega seemed completely out of place. TK and Patamon had like no time together this round (with TK being in a completely different location when they got separated. I'd go so far as that that evolution felt more in place in the last movie than this one.
All that said, looking forward to Ophanimon next movie (cause Magnadramon makes no sense, and the I'm going with the game megas as cannon -- as that has held up so far).