I have never sailed Princess but will very soon for the first time. I’ve sailed Carnival, Royal, Celebrity, and NCL. I LOVE the thermal suite. In my opinion it is the best luxury you can award yourself. On Celebrity the thalassotherapy pool was in general use area. On Carnival it is in the suite itself. 40 passes for 2000+ people is not a lot. The cost or up charges for cruising anymore have gotten out of control. No longer are you treated all as one class once you leave your suite/ cabin. It’s about paying extra for a lot of what you want. Up charging for meals, coffee, entertainment, adult only areas, pools, and sometimes theater shows is getting a little too Disneyland like nowadays. I think the thermal suite is reasonable to charge extra for because it’s not necessary. However, adult only areas, food, and entertainment should never be up charged as this is why we all cruise. It’s not like $1000 for an inside cabin is a great value when excursions and all other services mentioned are not all included. BTW even on Celebrity which s a higher class than Princess, does not charge for adult only areas. Also as stated the thalassotherapy pool was for general use. Something to consider.