I liked this one alot. Much better than Gaiman's last story. I do agree with the poster who thought that the Doctor should have left the kids in the TARDIS instead of taking a nap in the Wax Museum.
Smith's acting was quite good in this one.
I think Clara's personality being somewhat different week by week is actually part of the story arc. One of the reasons she's the Impossible Girl. She has become one of my favorite Companians of all time.
Moffat is doing a wonderful job with the characters and the show. He keeps improving, as opposed to the last showrunner who started out strong , but unfortunately started losing it towards the end (though his shows were still enjoyable).