I didn't really get tense either. I just thought it was baseline good. And the stuff at the airport felt kind of phony to me, like Affleck was just creating stuff to make it look bigger than it was. Another example was Arkin and Goodman getting held up from the phone. I just thought, just walk through the stupid scene already.
I haven't seen all the Best Picture noms yet, I'm missing Silver Linings, Amour, Les Mis, and Lincoln, but I'd say Argo is maybe the weakest so far. So far my favorite is, surprisingly, Zero Dark Thirty.