No tested ammo
I think the primary problems with this round for defense are:
1. No tested hollowpoint ammo. We are now using the 3rd or 4 generation of hollowpoint or defense ammo. I do not know of any manufacturer who is producing a proven design like the GOLD DOT, CRITICAL DEFENSE, HYDRA SHOK or any of the other exotic bullets for this caliber. Even the standard hollowpoint are in short supply and not proven in testing.
2. WHAT GUNS ARE THERE. Sure there are a lot of CZ-52's out there, but who wants to carry one. Put them up against a GLOCK 31 or 32 or a SIG-226 or 229. Which one would you carry?
If you just want a fast moving round for plinking or even small game hunting, it may due, but not for serious work. You need more than velocity.
Jim