A lot of it is what youre doing with them. If youre not wearing and sweating on one every waking minute, you will likely have a different experience than those who do.
I've tried pretty much anything you can think of as far as "trying" to rust proof a gun, and other than custom finishes, had little luck.
I will say that simple paint (Testors in this case), often does very well with hunting guns, and I have removed paint that was on a couple guns that were painted 15+ years, and there was no rust underneath what was painted. Areas where it had worn off would rust if not attended to though, but thats a simple fix too, just re paint it. Cant say how well it would work with a working handgun though, and especially one thats constantly drawn and reholstered. Even some of the custom finishes are affected from that wear.
Once I went to Hard Chrome, the rusting issue went way down to almost nil. I also own and have carried SS guns, and they too will rust, but again, not like or as bad as the blued/parked, carbon steel guns. Glocks Tennifer finish works very well, and actually better I think, than the Hard Chrome.