I bought a box of the ammo to shoot in my Kimber Ultra Elite. My thought was that it would be fine summer ammo and would get up to speed out of a short barrel very quickly. And, it does fragment quite well, into either 3 or 4 pieces. Conceptually, I really like the ammo.
On the down side, the stuff is wild! People talk about the flash from Hydrashok ammo at night. This stuff produces a whole vapor plume out of the front of the gun that has to be 12-18" in diameter and up 20 or 30" inches in length. It is the only .45 ammo I have shot where I felt the heat radiate back from the vapor plume. In the dark, the vapor plume is quite brilliant and very impressive.
Then there is the sound. The Aguila highpower ammo sounds about twice as load as normal .45 ammo. Every so often, I will load a round or two in my gun and enjoy watching the shootings to the left or right of me jump when I get to the Aguila round. It really is that much louder.
Buy a box and give them a try. They are a hoot.
I don't know if the lighter load is something I would count on for defense, although they are about the same weight as some 9 mm ammo and travel faster. The fragmentation stuff I have seen is neat because each fragment takes its own trajectory in the gelatin. I would say that if the shot did not hit bone going in, then the intended target would likely have some serious bleeding issues given that the 3 or 4 pieces, going in different directions, are bound to hit blood vessels.
I think I would be thrilled if Hydrashok made a similarly fragmenting round.