"He said his Sigma will be going strong long after I've replaced my Cougar."
Uh....no.
As long as you clean and lube your Cougar as a part of regular handgun care-and fire the -power- rounds the guns were designed to shoot-both guns should last the same.
I have to laugh when someone brings up a "My gun is better then yours" argument at the range.
They get a very quick-"Who give a "cheese sandwich" what you think about my handgun,i like it."