Bryan Espitia’s review published on Letterboxd:
It's a shame that this still gets lumped together with the other sequels, as well as the "torture porn" genre in general, since I think it's so much more than just gore for gore's sake. It's a gruesome movie for sure, hard to watch at times, but the torture itself isn't the main selling point here. It's part of a larger, very intriguing story, and just like our two main protagonists, the audience has to try and piece that story together like a puzzle.
The atmosphere probably enhances the violence, it's very grimy and disgusting and perfectly befitting of the world the movie inhabits. I will say that the editing can be a bit obnoxious at times, but it seems that was just the style at the time. And the acting isn't anything to write home about, yet it oddly works most of the time; Elwes and Whannell are able to sell the desperation of their situation pretty well.
It might not be James Wan's best film, but it's an important entry in the horror genre, for better or worse, and a legitimate classic.