I didn't find CapricaBoomer the least bit interesting until they got her away from Caprica. I think Grace Park's acting has improved this season. I think I heard that the actress deliberately made her somewhat stiff and unemotional due to her being a Cylon which IMO was a bad choice especially for GalBoomer who thought she was human up until she got on the basestar and whose stoyline I always liked.
Tyrol has really blossomed for me this season. The actor has really tackled the heavy dramatic scenes splendidly and I gained a huge amount of respect for him for his shipbuilding project. One thing that kind of rang false for me was Tigh and Apollo not supporting him instantly. They had to be aware that they eventually would have to replace ships.
On a related subject noone seems concerned that there apparently is only one doctor in the entire fleet; not to mention the technicans getting whittled down on Kobol. So far the only concern over training personnel is with the Viper pilots.