I made the same mistake. I expected the Proto to ride like camber, but I quickly realized it doesn't. It's a rocker and it rides like one.
I typically ride my misfit (camber and on the stiffer side) at 50 +. I took out the proto on the same slopes to see how it compares and it doesn't come close. Where it does beat out the misfit is in the park. It's more playful and pressy and I have no problems at sub 30mph speeds, which is probably what the average snowboarder stays around.
The main selling point of the NS hybrid profile is it adds edge stability that other rocker boards don't. Which I find to be precisely the case.
I'd like to see how the more all mountain oriented boards in the line stand up to traditional camber, but I have yet to ride them.
I would say I ride in the 40+ range most of the time, and have taken it over 50 many times too (admittedly this gets a little hairy especially if its chopped up).
I ride the proto out of preference, yes you need to be up on edge to make use of the camber in the profile, and yes you need to adjust your style a little.
I spent most of last season on stiffer posi camber and I find the proto is way more fun and can stay with it (close at least) when carving groomed runs at good speeds (not flat out bombing). It requires more angle and more fore aft movement for sure.
Obviously the other area where it shines is in powder where you get way better float and playfulness.
I don't do much park so I'll leave that to those who do.