I, personally, love the American version of this show, I watch it religiously and have seen every episode of all 6 seasons at least three times, except for a few in the 3rd and 4th when I was in greece, but I have to agree that the Christmas finale is better than any episode the US has put out, better than the Niagra wedding two-parter even, or the Beach Day episode, or the Casino Night episode, or The Big Gay Witch Hunt, although each of those episodes is better than any of the UK ones minus this special.
I did not know, and I made it a point not to find out until the end, so I honestly thought Tim and Dawn were not going to get together. I was surprised, and happy.
Thank you, Ricky Gervais.