Great review. The film is easily top 3 thrillers in my list.
I was already living abroad and freshly self-employed. I didn't see the movie until many years later, at home, on DVD with a projector and a screen. Fortunately, I lived a pretty sheltered online life at the time and had no idea about the twist ending at the end. It was a literal jaw-dropping moment.
The only things keeping me from re-watching after reading your review are that we're in the middle of "Stranger Things" and Kevin Spacey. I'm pretty good at separating actors' horrid personalities from their roles, but Kevin Spacey is a tough one to get over (like Mel Gibson).