Wife and 6 year old want hot tub, what should I get?

After a week at a rental house, the 6 year old is in love with hot tubs and the wife is also a fan.

Given the 6 year old wants to use it but will not want it quite as hot, I'm looking for something that can raise temperatures as fast as possible when an adult wants to use it.

My assumption from a bit of reading is Master is the best regarded brand these days and I like the aesthetics.

The unit will live outdoors in mid-Atlantic so we do get freezing temperature. Something that is as low maintenance as possible is preferable but not sure there'd be much difference between brands for that.

Appreciate any advice. Cost isn't really an issue but I'm not looking to just completely waste money for no reason.