I bought this Coleman on a whim two years ago. It's been rock solid and a huge help with pain relief. It's tipped me over into a real hot tub for my new house. It does not heat the incoming air when you turn on the bubbles, so the bubbles cools it down, but for less than $600, you can have a working hot tub that is enjoyable.
The only maintenance you need to do is change out the filter and for chemicals (in my case), I just make sure there's chlorine in the system. I'd recommend the square model if I was doing it over again. Add extra filters (about one every 4-6 days), float dispenser, and chlorine.