I really, reeeeeeeeeeally like how the show looks darker in this series. I also love it that, as you put it, they do throw in a few comical episodes to make it a bit lighter. The episode where Gaius is possessed by a Goblin is indeed one of my favourites =P
I could go on and on about how awesome some of the actors are, but I am indeed very biased and I admit that, hehehehehe! So I'll just stop here by saying that you can get some very neat acting lessons by just watching them