Not really any issues for your use with alloy frames other then normal scuffing and scratches from carry and when at range being shot alot the gun should be kept well lubed either with a oil or greese of good quality. The poly guns actually seem to do better for heavy use when carried or shot, lot of this will depend on the brand and caliber.
I CCW a Colt DE (10mm all SS) and sometimes a Sig 238 which is a Colt Mustang clone, but if I was in the jungles or desert and even walking the street it would be Glock for me. The Glock is a true military use handgun and is uber reliable and easy to use and keep clean and comes in about any caliber you want. I've owned three, two 29's and a 20, and the 29 's were super accurate, I was more accurate at 25 yards with the G-29 then with my Colts and Para.