just taking a poll.... I own both and know for a fact that the .357 magnums wins in both knock down power and penetration but which would you take if bad guy was in your house and their is no time to reload...the S&W Tactical revolver which holds 8 .357 magnums or a 1911 which holds 7 .45's in the mag and one in the pipe
The .357 is rough to control, and is limited to six (6) rounds. That makes it hard to classify under Obama's Assault weapons, but he will still try.
The .45 is better on control, and has less penetration, which makes it great for home defense, unless you can't take the round. Some find the 9mm easier to shoot, which gives the same stopping power, in the right round.
Unless you expect a threat to wear body armor or have multiple threats, I would opt for a less powerful round than the .357. You can be sued if you hit someone else, when the round goes through your house and car, and on and on. While you can limit this with the proper round, like a Glaser Safety Slug, the wrong round can be as bad as a rifle round.
Autos allow for faster reload, faster firing in most cases (Unless you are skilled with a revolver), and penetrate less.
Newer weapons hold more rounds, like you point out, but the rounds are the same. The only real advantage to the .357 is that you can sub-load .38 Specials for target practice, which saves money if you don't reload. If you prefer a revolver but like the .45, you can find some revolvers in that round, as well as the older .45 long Colt.
I own a Taurus 845 full size pistol that holds 12 + 1 of .45acp. I also own a 617 Taurus revolver that is a snub nose 7 shot .357.
.357 is my favorite caliber just to explain my position. Large enough to kill most anything but still not super heavy recoiling or over powerful.
In my neighborhood I would choose the .45acp due to the differences between the bullets not capacity of my 2 different guns. It's a bigger heavier bullet that goes much slower. It hits like a hammer but doesn't have the penetration power of a .357. With my residential area and houses very close I never want anything that can go through 4 walls and a baby crib just in case I miss. And in a stressful confrontation that is a very real possibility. I have kept the .357 loaded with .38 hollow points from time to time as a home defense gun, less penetration, less blinding muzzle flash at night, and faster follow up shots.
But my primary home defense weapon in a .12 gauge coach gun loaded with #4 buck shot 32 pellets per shell. Small, easy to handle shot gun that can stop an intruder dead but doesn't have the penetration power to go through my walls and reach out to my neighbors 100 feet away and go through their walls. I have a shell holder on the stock with 6 additional shells.
When you are close and need the firearm RIGHT NOW, you can always rely upon the revolver. No need to rack the slide. No worry about trying to recall if you have a round chambered already. Just point, flick safety and fire. Get the 357. Unless you find a 45 acp pistol using double action and keep one chambered.
For the "average" person I would recommend a .357 magnum over the .45 if those were my only two options. I say that because you can fire .38 (much cheaper) out of a .357 magnum handgun to save money on practice. If you're already sufficient with firearms I would get a .45. My personal preference is a 9mm loaded with +P.