James Y. Lee’s review published on Letterboxd:
Before Sunset is a magical experience. If "Sunrise" was about the spontaneous thoughts that these main characters had while they were still younger, "Sunset" is about them sharing their concerns for their future, their professional lives, and their marital relationships. It's a much more nuanced film and it definitely feels like the first film in terms of tone - there's still a sense of light-heartedness in these conversations, but touches on more ground that you wouldn't expect in a much more deliberate way.
"Sunset" takes place nine years after "Sunrise", where Jesse is now a successful author and Celine encounters him on tour. They spend the afternoon together, with yet another caveat - Jesse has to go back to the U.S. in about an hour's time. The two of them share their own conversations and experiences over those nine years, and it results in some very emotional and very wholesome moments.
The writing is as good as ever, but it is a drastic improvement from the first film. The scene that takes place inside of the car is absolutely amazing and is the complete emotional standout of this film. The dialogue is once again the greatest in all of forever infinity. In terms of character, though, you're even more aware in "Sunset" of these two characters' personalities and in particular how they've changed, and each passing revelation about their lives is something fresh and raw, and all of them hit like a brick.
The performances are still great. Ethan Hawke and Julie Delpy retain their great acting skills and their immensely great chemistry.
As for technicalities, the cinematography is now better, mostly because none of the scenes take place at night unlike the first film. There are a few continuity errors here and there, but they're so minor that they're really kind of not worth addressing.
All in all, this is a phenomenal second installment. I've grown to really like these characters and seeing them mature as more time passes is a great experience. "Sunset" absolutely delivers on both keeping these characters consistent and adding new things and experiences for them to say. The two films in this trilogy so far have so many different things to say about these people and about relationships in general, and the third film is no exception - but that's a story for another time. I love, love "Sunset".
Flight. This Time. A waltz.