IME, Hot Springs has always been considered the premier spa brand. I've had a Warm Springs spa for the last 19 years. It's been great, but Warm Springs was a local manufacturer that's been OOB since the early 2000's, so I'm on my own as far as maintenance and repair. As was mentioned above, there's nothing particularly unique about spa brands other than their design. The control panels, heaters, pumps and jets are all manufactured by the same small group of companies (Balboa, Waterway, etc) . I've replaced the circ pump twice, and each of the main pumps once since I've owned the unit. Pumps are around $150-$300, depending on HP. Spas are quite easy to work on.
My only advice would be to buy a spa with a circ pump and adequately sized filtration. I don't think the name matters that much other than perhaps for early ownership warranty issues.