There is something about CGI, particularly it's use in aviation sequences. I don't think it has been quite perfected. When an aircraft turns in flight always looks awkward. At this point in time you still can't beat real flight footage in films. I know it's probably expensive and not practical these days, given you simply wouldn't have 100+ B 17's or whatever to muster into the air. Favourite aviation flicks of all time(purely from an aerial action point of view);
Memphis Belle
Battle of Britain
Empire of the Sun(Mustang scenes are amazing.)