Ogata and Maria are god damn on point with their facial expressions. Ogata surprised me, maybe it was her ice skating training, but her expressions are like a professional. Everytime she was on screen she looked amazing, and with the right sort of mood too - like she new exactly what she was doing. Maria was so good, too, but hers was like - this natural kind of ease in front of the camera. If these two became faces for MM I wouldn't complain.
Haga has this awesome like... cold stare that I just can't get over. I noticed it on her concert Towel, but I kinda fell in love with her as soon as she popped on the screen looking all:

Miki needs some expression work, she had no idea how to move her face but it isn't too bad.
Dancing wise, Miki and Maria are best. I saw Haga go awkward a few times and phheww... Ogata... you really are the new Haruna. I'll be rooting for you!