3. Unconvincing
The Doctor's companions since time immemorial have always been the eager beavers, wanting to go off adventures with him -- hello, time travelling genius. But modern day Clara, it seems, have reservations going off with him. Of course it isn't an easy decision to make with a man who just saved your life and shown you that you can take a shortcut to tomorrow -- right. What is there to think about, again? All right, it's good that she cares A LOT about her pseudo-family, but against time and space travel? Basically she just wasn't that convincing.
2. All Over The Place
After five episodes we still haven't any idea who this impossible girl is personality-wise. Sometimes she's a too-wide-eyed teenager off to see the Universe, and then goes a bit too cavalier about the Doctor. She seems to have not yet established her own character, which might be a part of the whole mystery to the character itself, but at least be consistent of how the personality is supposed to be. In Cold War she seems to be lost half the time and spends the other half asking the Doctor if she did good. She was off to a good start with both Asylum of the Daleks and The Snowmen but is currently, in recent episodes, all over the place. It can't be because of the whole Impossible Girl situation, as however impossible, she still needs a consistent personality. Without the Impossible Girl bit going for her, she doesn't have an identifier (yet, at least).