The episode was very surprising to me. It wasn't very typical for the show. First, the episode mainly took place in Michael's home not at Dunder Mifflin. Because of the set change, much of the cast was not included in the majority of the story. The only characters were Michael and Jan, Jim and Pam, Andy and Angela, and later Dwight. These are the main characters, however a lot of the humor comes from the minor characters. It is surprising that they were cut out of the show's return.
The plot was surprising as well. It is not that it wasn't funny, just very unexpected from the characters. Much of the plot focused on Michael and Jan's tension at home. They were both out of character. Michael wasn't trying to be funny and failing at it. He actually spent most of his time mad at Jan. Jan acted the same way towards Michael. They were both blatantly disrespectful of each other, where as they usually try to remain calm in public.
I think the plot was a good one, but I think it made it difficult in that it premiered the last half of the fourth season. I feel like it could have been written all along, and there just happened to be a long break in the season. I think everyone was expecting to be reunited with their favorite characters and then spent the half hour in Michael's house with Jan.