Anybody got one of these? If so, what do you think?

I put a swim jet in the deep end of our pool when we built. I've not used it nearly as much as I thought I would. My biggest feedback is that if you can go to a showroom and test one out, do it. My jet puts out a steady stream for 1-2 minutes then feels like it backs off then goes strong again. My guess is that the swim spa has a better propulsion system. That said, it's just different than a pool.

I noticed Lionel Sanders trained in one for a season. I've not seen him in one since.

I tried one at an AirBNB one time. I felt like an absolute dumbass using it. Could not figure it out.

I came very close to putting one in our pool when we built it. I ended up not doing it, and glad I didn't. In the winter time, id have to heat the entire pool and that would be expensive. So its probably cheaper to just join a gym.

Joe skipper was/is trying to sell his too. Just another data point, pro triathletes swim in a pool or open water.