Darren Carver-Balsiger’s review published on Letterboxd:
Before Sunset is a much better film than Before Sunrise but I only realised that at the end. The ending of Before Sunset is fantastic, a perfectly understated moment that now makes me nervous to finish off the trilogy. Unfortunately to get to the ending requires slogging through the rest of the film, which is just boring and uninteresting.
Just like Before Sunrise, the film is just a series of mundane, pseudo-philosophical conversations revolving around a collection of unlikely anecdotes that all conveniently tie into philosophical ideas. Some moments, such as the meta opening bookshop interview, are just straight up irritating. I also couldn't stand the bit where Ethan Hawke talked about how we are each the sum of the moments of our life. This is an obvious point that Linklater keeps hammering home by literally spelling it out in his movies. I've only seen four Linklater movies but this is the third (after Before Sunrise and Boyhood) to talk about how our lives are made up of moments. We aren't idiots, and you don't need to explain the same simple thing over and over again in your films. Then again, the two leads here are people that are "open to anything but don't buy into any one belief system," so they're not exactly people who have given serious thought to the topics they discuss. Still, you have sit through these ignorant ramblings to get to what good the movie has to offer.
The lead couple do have some really believable chemistry though and Before Sunset strikes me as a truer, more genuine, probably deeper film than Before Sunrise. The setup is better conceived also and the long tracking shots are wonderfully executed. It also has a real time gimmick which actually works, which is surprising given Linklater's penchant for arbitrarily setting a time limit that serves no purpose.
So, all in all, I guess Before Sunset is technically better put together than Before Sunrise. It's certainly a sequel that compromises and doesn't do anything with the previous film's ending (one showed up, one didn't, once again the will-they-won't-they remains ambiguous by the end) but I really loved the way Before Sunset bowed out even if the rest of it did little for me.