I work for a pretty large agency and we carry the Sig 227 as our primary and the 365 as a backup/plain clothes carry. I work mostly plain clothes so I carry the 365 everyday. I personally like the 365 and haven’t had any problems from it or the 227 after firing well over a thousand rounds out of both. Having said that, I’ve carried Glocks in different flavors as well and own several and like them.
I say all that because when we first got our 227’s we did have problems with them and we had to turn all our mags in to get replaced and that seemed to solve the problem. They delayed the issuance of the 365 because of problems with the first batch we got. As a whole, our agency has had some rust issues and our firearms guys always tell us to make sure we clean and wipe down our guns especially if they get a little wet from rain, humidity, etc. We are also told to take our mags apart from time to time and clean and lube them as well because of rust. I just look at these things as normal maintenance things that I do to all of my guns. Again, I like my 227 and 365 and trust them daily with my life, the same as I do with my Glocks and my Smiths that I also own. Along with my rifles I have. If I can’t trust it, I don’t own it but yes the 365 will rust at least some do.