Sadly he never reached his potential (partly through injury and partly through having the wrong attitude) but he still achieved a lot in his career and helped us win some big trophies. He was impossible to tackle on his good days, he was brilliant at recycling the ball, and he was a beautiful player to have alongside David Silva in those Mancini and Pellegrini teams. He was vital in the title charge in 2012, then vital again during the last 2/3 months of the season in 2014. He was never quite the same after that ankle injury at the start of Pellegrini's second season, which seemed to start a chain of injuries that he never got over, and by the time Pep arrived the standards were much higher than he could keep up with. But still, that doesn't mean he wasn't a classy player. He came in handy, had some great games for us, scored a goal in a League Cup final, and did that amazing celebration with Djibril Cisse after the Aguero QPR goal. Not a legend, but still a key member of the first City team to win the Premier League, so absolutely deserves a warm welcome whenever he comes back on a visit.
P.S.: He has one of the most underrated debuts in City history. 3 assists away at White Hart Lane, during a period where they were a bit of a bogey side for us, is one hell of a showing.