I've finished S2 now....my thoughts:
I love Carol.
It was sad to see Shep deteriorate and refuse help (in reality he probably needs several months off work for burnout/stress, I don't know if you'd get this in the US).
I would like Jen (Mark's wife) to go away, she is annoying.
Carter is a jerk too often for me to like him.
I was impressed with Benton's integrity (with the dodgy clinical trial).
I think I'm supposed to hate Kerry but I actually like her, she says many reasonable things.