I'll have to watch it again - the joys of a family Christmas meant it was competing with people snoring, asking what was going on and whether Dervla Kirwan was evil, having coughing fits, wandering back and forth in front of the TV to get to the bin, etc. But I think it was the best Christmas ep since The Christmas Invasion. Which isn't saying much, I realise, but still.
Random thoughts: lots of continuity, some good, some not so good. (Oh, a Cyberman escaped extinction by falling through the Void into the past. I wonder if it met the Last Dalek on its way.) I was prepared to get annoyed about the lack of Donna mentions, but we got one at the end, more or less. The Doctor gets thanked all the time, doesn't he?! And Jackson must have a Very Loud Voice, considering how many people seemed to hear him do his "Yay Doctor" thing and start applauding. MegaCyberman reminded me of Abbadon from Torchwood but better, so that was good. If one must have an "Oh noes the poor children" plot, I approve of none of them actually having any lines, heh! I thought Jackson's son was going to get through the whole show without a name, too, but I think they named him near the end...have no idea what, due to background noise. Cyberfurries, wtf? And did the Cybermen in our universe ever use the earbeads - wasn't it just the Cybusmen? I can't remember if they used them at the end of S2.
And of course, w00t! .75 seconds of Chris Eccleston! Worth a whole extra star, that.
(Actually, that reminds me - was this the first Christmas ep there was no tortured "Christmas star" reference, and the snow was actually snow?)
(Oh, my day's been good, hope yours has too...)