I like it, it puts a more serious/adult perspective on the Doctor Who Universe. 
Basically, how dangerous something such as say a Cyberman really is when the Doctor isn't around to save the day.
So I'd recommend that any Whovian at least give it a shot.

Just note coming in that they do put a lot of focus on the other members of Torchwood too and it's not going to be a show focusing primarily around Captain Jack most of the time.