He's at his best making runs behind defenders, getting in the box to finish off moves, taking on full backs out wide.
Now either his demands to play through the middle, or Wenger's belief that he can replace Cesc (or maybe both!) has seen him spend most of his minutes during pre-season behind the striker, and it's painful to watch. Personally I find it hard to believe that Wenger would allow a player to dictate who he picks in what positions, but I do feel Nasri has an ego beyond his talent, and I just get the impression that he doesn't realise his own failings there.
As I've said before, if City offer £20million we should deal.