It's hard to judge Smith as the doctor because, while he's still fine in the poorer episodes, he probably had the best material to work with. That gives him a more ground than he's have if he was acting in the last few seasons. Tennant handled some shitty, shitty situations with ease.
That one underground episode last season was terrrrrrible and his line "you are so not the very best of mankind!" wait, what? it came off as goofy and no sense of authority. Of the new seasons, Eccleston was the best getting mad because he acted like he could burn your soul with true and spiteful remarks. Smith just sounded bitter, like he was picked last for dodgeball or something.
