...and I thought it was brilliant. And now I have decided to watch the entire series. The first episode I saw was the last Christmas special which didn't really make me interested in the show. However I much prefered this special.
If you liked this special you might be bored by the early series but I still would recommend watching it. You have to give it a chance and watch a number of episodes though.
I'm saying the early series is very different than the last two specials. If someone likes the two specials, they may not like the early series because the humor is very different. In the specials the humor is very silly and over-the-top. In the early series the humor is subtle and all they really do is sit around watching TV. I love the early series because of those things but I it wouldn't surprise me if someone who liked the specials didn't like the tone and subtle humor of the early series.