Well, after an official second watching.. it only got better.
My one complaint remains that the death scene drags out to long. But it is a horrifying death / idea, so in the end I'll cut it slack and let it slide.
Besides that, I personally really have no problems with it, at all. I think this is brilliant Doctor who, as it should be. Spooky, with a perfectly woven plot that doesn't seem to slow down, even when they're not moving from set to set, great direction, great acting.. plenty to keep you thinking.
Plus, I now can -not- wait for next week.
All in all.. 10/10. You've done it again Moffat!
First episode I've ever rated a 10/10 on these forums, I do believe. Hopefully next week will be even better.
I will be glancing at shadows a bit more often, from now on though.. and all that dust in sunbeams. Just like the whole statue thing after Blink last year. Dammit.