You don't need to dig through foam to try and find the leak. You just pop the jetpak out. It doesn't even require a tool and the water does not have to be drained out of the tub, as is necessary in most other tubs.
There's a lot in this post that is nothing but salesmanship but alas who has the time.
Most tubs have slice valves that will isolate where 99% of the leaks I repair are. The equipment bay. And with no diverter valve how do you control the pressure if you prefer it lower? A diverter is not a bad thing.
As has been addressed, each jetpak has it's own valve that adjusts pressure in that particular jetpak. Once again you point out a negative to a hot tub that you obviously aren't familiar with. This is my biggest beef with you, though I wish you no ill will. I think you formed an opinion on Bullfrog from some of their older tubs, which I will admit aren't very nice. A modern Bullfrog kicks butt! No hard feelings buddy.
Also, the industry is going away from using slice valves. There are quite a few major brands that quit using them.