Well, I've wanted a hot tub for a long time, and it was a "bonus" when the house we just bought came with a somewhat neglected Jetsetter JJ, purchased in 2006. It was running at 102° with what seemed to be plain water for probably a couple months before we got it.
I've got a Taylor K-2016 and am trying to run bromine-based sanitation. I've traded out the filters, shocked it, and gotten the bromine levels up. The pH is a yo-yo with trying to get the TA up and the pH down, which is getting me to the point of deciding to just use an enzyme cleaner (I've got SeaKlear SpaKlear, prior to reading of the better performance of Ahh-Some), draining it, scrubbing it, and starting over...
My wife calls it my new aquarium, as far as water balance goes. At least there isn't a CO2 system to manage as well!