Not impressed honestly. Probably because I was already familiar with the Governor's personality and knew what he was going to do already. I can imagine that someone who was never exposed to his character might be shocked by his actions.
Well, I think they made him more believable than in the comics. I risk offending die-hard fans when I say that the governor is a fairly generic, one-dimensional comic book villain. The TV show's version is more complex and more believable, IMO.
Same goes for Michonne.
I think Michonne and the Governor are two difficult characters for TV, and most directors/ producers would have botched them. Thankfully, everything seems to be working out fine.