I love revolvers. But I sounds like someone needs to defend the good old 1911, so I'll do it (easy on the flames, folks
)
We'll start with the round. The .45 ACP is a great round. The 230 grain .45 ACP hits hard and penetrates very well. Yeah, I know, the 158 grain .357 Mag is awesome, but it will have a lot more noise, flash, and recoil. And shooting a .357 mag out of a snubbie revolver? Ouch. You won't want to practice much, and those rounds are hard on a snubbie revolver. Expansion is less of a worry with the .45. After all, it is a .45, so even if it doesn't expand, you're still starting with a pretty big hole in the first place.
Now we'll go to the trigger. You can ask Springmom about the advantage of a single-action trigger. With the 1911, you get the same light, crisp single-action trigger for every shot. I know that you have this option with a revolver, but in a crisis situation, you may be more likely to shoot the revolver double-action if you've gotta shoot quick. Generally, most shoot more accurately with single-action compared to double-action.
How about capacity and reloading? With the 1911, you have 9 shots instead of only 6. This may be a factor if you are facing multiple threats who are shooting at you. And the 1911 lets you know when it is empty by locking back the slide. Then you simply hit a button, slam in your next mag, and release the slide -- and you're right back in the fight. Compare to the revolver: you realize that your gun is out when it goes "click" (you lost count while you were shooting and being shot at). Then you hit the latch (admittedly not any harder to hit a cylinder release latch than a magazine release), eject the empties, and load six rounds. I hope you have a speed loader, and that you aren't trying to twist when you should push (or the other way around); plus, you have to be more precise to line up those six rounds exactly right w/the holes in the cylinder. Now swing the cylinder back into the gun, and you are finally ready to re-engage. In the (seemingly forever) amount of time it took you to reload that revolver, I've already shot through my second mag of .45s.
Ease to conceal: on good thing about the 1911 -- it is flat without that bulging cylinder.
Reliability? A gun (whether semi or revolver) is either reliable, or it ain't. If I've taken the responsibility to legally carry concealed, I've made sure that whatever type of gun I'm carrying goes bang every time with the kind of ammo that I carry. And don't make the mistake of thinking that a revolver can never fail to shoot. Cylinders can bind. Mainsprings can break. And those pesky internal locks in the snubbies can engage at exactly the worst time.
O.K. I've done the best devil's-advocate job that I can here. Now be nice!