I have. Did it once and never went back. For me it was not pleasant. My wife had gone in first and the machine basically went from room temp to minus whatever they set it at. So when I stepped it, was already freaking cold. They they make your spin around slowly during the process. I can’t remember why, but they do. Now I’m not a big guy but my shoulders are pretty wide and I kept bumping into sides which wasn’t comfortable. Did I mention that you go in your undies?
Anyway after it was all over, I did feel pretty “hyped” or pumped up and it lasted a while but considering the cost, the moderate inconvenience, and the uncomfortableness of it, we didn’t go back.