True Story:
I sold an "Oasis" to a surfer. This was the first one of these Caldera-derived tubs I had ever sold. The customer was insistant that it go above 104 so he could come home from surfing (two blocks away) and slide into a very hot tub.
After selling Watkins' products since 1986, I was sure the thing would act like any other tub I had sold. It was not to be: the Oasis uses a Gecko spa pack, and it goes right to 104 and that's it. I swapped the sensors a couple of times and got exactly one HALF of one degree more.
I ended up taking the tub back, and making him a great price on a Prodigy. That tub, went to 108 as do most HotSpring and Tiger River spas will.