I just saw the third Ethan Hawke and Julie Delpy movie, "Before Midnight." If you haven't seen the first two movies [I'm sure they're available on Netflix or DVD], I'd suggest 'catching up' on the background before heading in to this one.
I loved loved loved "Before Sunrise," which came out in 1995 and takes place primarily in Vienna. Wow, how time flies! And then I enjoyed "Before Sunset," which takes place in Paris and was filmed in 2004. Now this newest addition takes place in Greece 2013. So they've continued the story of this couple with an installment every nine years and it's really quite interesting to follow the progression / changes in their relationship and lives.
Essentially, they are movies of dialogue and more dialogue. The screenplays were written, in part, by Ethan and Julie; so they're delivering their own lines. As I watched this afternoon, it was easy to forget I was watching a film; it really put me in a "Oh yes, I've been there and done that" kind of mood. I'm still digesting it; I'd be interested in others' comments.