I've been a fan of Cumberbatch since the first season of Sherlock. I knew he was an immense talent and would absolutely kill it as Strange -which he did.
I suspect a lot of the film's success is owed to his spot-on performance and the performances of the other main cast (Swinton, MIkkelsen, Ejiofor).
If a less talented actor had played Strange, I suspect this film would have scored much less on RT.
Anyway, I'm going to make a big call here and say that BC embodied Strange, the same way RDJ did in his first appearance as Iron Man.
Truly perfect casting !