That doesn't mean that the 45 is a wimp though. You have to consider your intended use and target. I use 45 as my city gun, because people fall down pretty fast to a 45, whereas I use a 44 Mag as my mountain gun because for critters that bite and charge, I may need more penetration than the 45 offers
The 44 Magnum cartridge can still be used in the city for personal defense. Speer makes their 200 grain JHP short barrel self-defense cartridge that has reduced velocity (~1075 FPS). It outperforms the 45 ACP cartridge in terms of stats (energy, velocity, etc). Its performance on living tissue is unknown to me. My guess is that it is on the upper end of performance but within the range of acceptable performance for use against humans.
It's not too flashy and recoil is not insane. Follow-up shots are pretty fast.
Well the fastest to shoot in controlled fashion, by far would be a moderate recoiling .45ACP semiauto, but the fastest bullet of 200-230 grains will come from the thumping .44 Magnum revolver, by far.