I'm am old school guy and was opposed to "plastic" guns from the very start, always felt that you can't build anything strong and long lasting out of plastic. Plastic is for disposable items like Solo cups. Also agree with Snake45 that most of the poly-framed guns are fugly. How could anybody fall in love with a weapon that looks like a Glock? Let the flames begin.
But times have changed and even an old schooler can learn a few new tricks.
Like most poly-framed guns have their slides and other moving parts running on steel inserts, and all other things being equal will outlast all the famous aluminum framed guns that came before when it comes to high round counts. Steel against aluminum just doesn't make for a great bearing surface.
And as for the fugly looks, IMHO Ruger changed all that with the release of the SR series guns. To my eyes the SR9 was the first poly framed handgun that had the smooth flowing lines I appreciate in a handgun.
A large part of the success of the SR series, LCP, and LC9 guns are that they just happen to be the best looking in their class.
Like any tool there are a number of tools for every job, some just excel on some jobs for their unique aspects.
I've truly learned to love the lightweight carry aspects of my poly guns. My TCP just drops in my front pocket and I forget I'm even carrying it. When I feel the need for more firepower my SR9c holster carries better than anything else I have. There are some days I get nostalgic and will carry my Security Six or SP101 cause I truly love my revolvers, but after a day of having the chunk of steel hanging on my pants makes me appreciate what modern weapon technology has brought.
Sal