It seems to me that the Bowling Moms and Chip and Kim are pretty happy all the time.
Chip has had some of the best subtle one liners I have ever heard. He is always smiling and seems to be not taking things too seriously.
I think he is still focused on the race, but seems to be happy throughout. Aside from the cab incedent, (which at that time he had to do because he though he was in last place) he has always seemed to have fun.
There is nothing wrong with running an intense race, every team is bringing different personalities. I like the mix of characters, love them or hate them there is good contrast this year.