I never really bothered with magazine extensions on my CCW guns because I’ve mostly learned to stick with the standard capacity magazines instead of trying to turn the gun into something that it was never meant to be.  For instance the Sig 239 is a great CCW gun and although you can put a 10rd magazine in there, the profile of the gun is going to change and depending on the clothing that you are wearing,  you may have just created a snagging location or a hang up on your shirt.   Sometimes moving around a little with your CCW method will give you an idea of how your clothing may bunch up or scrunch up in certain areas around your gear.  The Material of various shirts makes a huge difference and even though it light flow straight down over your gun, high winds can cause embarrassing situations with even the smallest CCW gun.

I never witness there being a difference in 1911 reliability between 7rd and 8rd pistol magazines but I’ve always felt the magazine durability has improved enough to get 8rds out there.  I have noticed some gun magazines have increased their capacity but the Chip McCormick magazines that I use are the Power Mags and they have a slight magazines extension that helps with faster reloading.  All of my 1911s drop these mags without any snags which is something my Colt factory magazines do not.  Drop free magazines are important because that is one step that can slow down a reload of the firearm.