There is nothing wrong with poly guns -- except esthetically, and I won't ever buy one. I understand the attraction...and the price issue....but I still don't want anything to do with them. I have fired most of the Glock, HK, Springfield, etc poly models ...and I have recommended them to some of my grandkids or the young adults in my family as solid guns / the new Gen 5 Glock is a pretty nice gun as an example.
I know I'm in the minority wanting nothing to do with poly guns ...but that doesn't matter either. I'm in my late 60's ...and its a generational thing partly ...some of my buddies agree with me / some have gone to Glock, HK, etc..for their primary guns. 1911's are the gun of my generation ...and I shoot my Wilson Combat, 5", 1911 in 9mm...most every week in my "buddy" competition Tactictal shoots...and I hold my own / in fact in last 2 yrs, I have led the way at an average of around 95%, so I'm sticking with my 1911's in all stainless.
In terms of weight - for the most part we are talking about less than a pound...between most of the poly guns and an all steel gun like a 5" 1911. 1 lb is not enough to make a difference on my belt....so I choose to carry a full sized 5" 1911 in 9mm ( 10 + 1 rds is plenty ) and I carry an extra mag...not because of capacity, because the mags are the least reliable part in a semi-auto.
A solid belt, a good IWB horsehide holster..and a 5" 1911 is easy to carry. I will once in a while carry an N frame, S&W revolver, a model 627, 2 5/8" barrel, 8 shot, .357 mag...( all stainless )...and a speed strip in my pocket for reloads. No poly needed / or wanted here.