:cb2: Doug, I'm an avid wheelgunner. I love my revolvers, all my DA Smiths and my Ruger SA fun guns, but I've carried a Glock 21 since 1993, and it's my #1 go to gun for self defense, for all the reasons the other guys have listed above. I first settled on the Glock because it had 50% fewer parts than other automatics at the time. (Now everbody in the world has copied it.) That means there is less to go wrong. And you know all about the torture tests.
My wife's .357 had the cylinder freeze up on her a couple of times, but that was after several (5-6) boxes of reloads that were quite dirty. However, that was in a pretty clean environment with no dust or sand at all added to the mix. Now that means removing the cylinder in order to clean it and the yoke assembly. On some revolvers that can be a pain in the nether regions. Glocks . . . well, the problem just doesn't exist, and like others here have said, they just keep on shootin' when other guns won't.
I will still carry my wheelguns for hunting and fun stuff, but when going into dangerous areas, my Glock 21 is my pal. (My S&W 57 is secondbut not a close second!)I think the Glock 20 is a terrific choice for what you want. The 10mm is pretty darn hard to beat, and the recoil is pretty tame. (My wife shot one and loved it.)
Go for it! You'll be extremely happy you did.
Besides, if Savage and Joe (sos45-70) say it's so, you can bet it's a sure thing!