I thought it fell flat. Watching this special was like watching a commercial for a movie that looks like it ought to be pretty good. Stuff happened, and characters hammed and shouted and quipped at each other, but it didn’t convey to me any emotional impact.
I think The Next Doctor is the best of the Christmas specials. The monsters — which would look really good in a Doctor Who version of Temple Run, by the way — are goofy, but it also has anguish and joy and pain and healing all mixed together, without using pre-approved cutouts from The Fandom Book of Feels.