I was very worried about how the Mandarin would be portrayed. Considering that the Mandarin is an outdated and racist caricature, I felt there was no way to have the Mandarin without controversy. I mean look at the casting: when Kingsley was announced people were like "that's racist, he's not asian!" but even if they cast an Asian actor, people would still have been like "that's racist because he's asian!" Damned if you do and damned if you don't.
I think it was a brilliant move for Shane Black to create such a self-aware character. It was supposed to be caricature that fed on American racism and terrorist paranoia. I think the thing that got me was when Killian yells, "I am the Mandarin!" at the very end. I thought that was a little over the top, but again it did not ruin the movie for me.
Iron Man 3 is hands down the best of the trilogy. Iron Man was bogged with origin story syndrome and Iron Man 2 was a 2 hour commercial for the Avengers. Iron Man 3 was funny, had the best action scenes, and had a story that had me on the edge of my seat many times.