The bugs were to do with firmware fella. I read on the forums that it ran smooth after the last update. They finished the game then Sony updated the firmware ****ing up the framerate etc, Sony updated the firmware and it was sorted.
I bought back Ferrari C when it had Trophies added and it made me a better play as you had to nail the game to get the Trophies. In fact they are the hardest Trophies I've tried to get in any game.