I was never a big fan - she tried to 'do' attitude and it just came across as obnoxious. She tried to 'do' confidence and it just came across as heavy handed 'look at me aren't I hot'....
...until I saw The Impossible Astronaut. I thought that was her best performance by a country mile - she was sassy and confident but that unpleasant edge has gone. As I said elsewhere, I don't think it is any coincidence that this was an episode where she was not objectified or oogled or put in a short skirt. Instead she integrated well within the crew, she showed determination and loyalty to both the Doc and Rory. It was such a pleasure to see. If this is how Amy is to develop across the season then I think it is a most welcome development