I also rotate my carry between Glocks and full-size 1911s. I think I mentioned this in a thread a day or so ago. Because my carry 1911s are blued moly steel, once "sweat season" is upon me, I have to revert back to carrying my Glock. Say what you will about a Glock, but those things are just about impervious to rust and corrosion (I'm speaking of the metal parts, obviously). The only rust I've ever seen on mine emanated from some aftermarket sights that I'd replaced the factory "slot protectors" with. But... I just gotta get me a pair of stainless 1911s... Then the only excuse for my carrying a Glock would have to be, "just because I felt like it." Come to think of it, that's not a bad "excuse" anyway.
Also, as I've also mentioned previously, I switch to the Glocks when working out-of-doors. I tend to bang whatever I'm carrying up against machinery or whatever it is I'm working on or around, and I really hate to subject my 1911s to that abuse.