I live in Miami and we went back and forth about whether to add a spa or not. We liked the idea of jets and "sitting around" and relaxing. But, it is so hot here, friends warned us we would never use it because it wasn't refreshing. We're adding a "spa area" but not a true heated spa enclosure. It will have the jets, the seating area, and some sleeves to add umbrellas for shade, but it won't be a completely separate space with its own pump and heating. Honestly, I'm very nervous about this decision. It could be a fabulous idea or a total flop -- a really expensive one!
I think since you are from North Texas, I would try to add one if at all possible.