A lot of what ST says is absolutely true, he tries like fuck, he does all the ugly stuff, he harrasses the fuck out of defenders but there is no substitute for ability.
But again he has been picked by a succession of managers, though up until recently that meant very little, they were pretty much clowns.
Calderwood sees something in the guy and he is more qualified than either myself or anyone else on here.
One other thing, he does have a habit of scoring important goals.