I've heard from a reliable source that the KBlade Pro Stock is actually a paint job NBlade 98, which is actually what Raonic is using.
I have two H22s, not sure whether it's the stiff or flexible layup, but they are much harsher than the retail Blade, especially the newest one. I've gone through other H22s in various paint jobs, and for whatever reason they all tend to irritate my arm. If I could use one without having that happen then I would switch to it. They all tend to hit the same for me. Although I don't doubt that there are different layups, perhaps there's a stock layup and then special layups that a pro can order if he's ranked high enough and/or doesn't like the stock layup.
Compared to a 57e, the H22s that I've used are still significantly more powerful.