This show is great, no doubt. My only real complaint is his sister. Just not too fond of her character (which I'm sure is supposed to be annoying, but still). It could be the actress, but she didn't bother me in films I have seen her in, she actually seems like a decent enough actress.
About Hall being such a phenomenal actor..
I haven't seen him in Six Feet Under, in fact I havent seen him in anything except Dexter so I can't really properly judge him I guess, but I do feel like he has his ups and downs. Sometimes I feel like he's really conveying the character and sometimes I feel like it's not all quite there. The clips for the new season appear to show him being a bit over the top....I do take all this into consideration being the character of Dexter Morgan (sometimes he's up, sometimes he's down, sometimes he's crazier than usual) so I suppose it all makes sense. The episode where he had to help his "friend" in the hospital, with the key lime pie...I felt like that was a truly pivotal point in his character portrayal.
I'm definitely psyched about the new season. What sucks is I've been watching season 3 all summer because I hadn't seen any of it prior, and last week they showed clips of the ending of season 3 (Before they aired the freaking rerun episodes I was about to watch!) and it totally gave everything away. A little disappointing, but it's all still a good watch.