I haven't seen any of the previous movies (I know, I know) but I really loved watching the various conversations unfold in such magnificently naturalistic long takes, complete with false starts and stops, digressions, inappropriate remarks, and so on. The thrill of having a relationship like that, where the other person is so addictive to talk to almost to a fault, (it might lead you to ignore other problems in the relationship - or maybe this is a good thing, I dunno) is captured perfectly.

Key line for me is probably "let's stop talking so we can fuck." Easier said than done.