Him, Clark, Gana, Veretout, and others in the recent past - all buggered off and appear to have made improvements in new surroundings. Of course, they can't be totally absolved of blame for whatever they failed to do while with us, but we really do have this unfortunate habit of not getting the most out of players with some ability about them (as opposed to genuine hopeless cases.)
I suppose the counter-point is that the likes of Gestede and Ayew haven't been tearing up trees since they departed, in that it suggests of what a mixed bag things can be, but we're always going to be swimming against the tide if we can't develop players properly.
