If you're going to get one, highly recommend getting 240V instead of 110v/plug and play type. 240V are the only ones that can really keep up with the heat and give you that real jet feel in the tub.

If possible, keep it somewhere covered. We have it in our covered patio, which allows us to get use of it in any kind of weather and prevents mosquitos/other bugs coming around.

Chemical balancing can be pretty tough, we mostly keep a steady supply of bleach around to make sure it's staying clean. One issue we had was the test strips never seemed to say the water was hard enough so we kept adding calcium hardner, but it ended up precipitating and making a rough coating on the seats (eventually we were able to clean it off). Ended up deciding it wasn't a big deal if some values are out of range on the test strips as long as the stuff to keep people safe is balanced (ie chlorine)