My point is that an antimatter bomb is not like the worlds best weapon or anything. "All of the matter is converted to energy" doesn't mean as much as you would think. Most of the energy (about 60%) is carried away by neutrinos, which have almost no interaction with matter and thus escape into outer space. Therefore the antimatter bomb isn't exactly as efficient as you would imagine. Still, a kilogram of antimatter, collided with normal matter in the right way would be devastating anyways.
