Actually,we did "test soaks" of all 3 models(I would not comment on the comfort aspect of the tubs had I not). I did like the "motomassage" jets on the Grandee,however,the Maax spas jets and configuration seemed much more therapeutic to both my wife and myself. We both also liked the jets in the lounge seat that hit on the tops and soles of your feet at the same time and also prevented my wife,in particular,from floating out of the lounge seat.The warranties on all 3 tubs are virtually identical(actually the Maax has a longer structural warranty due to the steel frame) and their respective energy efficiency ratings are similar, so where is the "step up" that you are referring to?