I had seen the trailers and certain online spoilers for this episode and waited with eager anticipation. I finally sat down to watch and man did it live up to the hype.
I agree that it was a tiny bit slow in parts but the nostalgia aspect maintained the episode's watchability.
Parts of this story were set along the Western front during WW1, 1914... at Christmas time - so if you know your history, you will notice some foreshadowing for the upcoming narrative.
Everyone knew, myself included, how the story would end (Unless you have been living under a rock... on Gallifrey!) but it was still nonetheless captivating and goosebump-inducing to witness.
Peter Capaldi's Doctor had really grown on me, his delivery of some really laugh-out-loud lines with expert timing endeared himself to this viewer. That said, I am very eager to see where the cliffhanger takes Jodie's incarnation of The Doctor in season 11. 8/10