I've finally caught up and have to say that Tennant has really grown on me as far as being the Doctor goes. He is definitely not as dark as Eccleston (who was, as near as I can figure, having no previous exposure to the mythos, a great Doctor), but I see no reason why he has to be. He is definitely carving out his own niche and I find his portrayal quite enjoyable while not taking anything away from everything that Eccleston did with the role.