I don't suspect that my experience relates all too well to the question, due to my background in handguns... but I'll share it and my philosophy also.
I had been owning and shooting handguns as a hardcore hobbyist for many years before I ever even considered the idea that I would ever carry concealed. One of the main things I needed in a carry gun was something I would never worry about getting worn, scratched, banged up, sweated upon, etc. I'm emotionally attached to my favorite handguns, so something that would be 100% "tool" was what I needed.
So when I made my choice in a carry gun, it came about as a result of silly emotional ideas of what caliber I'd carry... more so than what actual handgun I'd carry. I grew up in a world where we all simply -KNEW- the 9mm was wildly inferior and the .45 was a "far better" answer, but the .357 was the finest idea of all. I grew up reading Guns & Ammo and specifically, Jeff Cooper. (these ideas have since EVOLVED!)
So when I got the wild idea to get a carry license, I was going to carry the round that I felt personally attached to: 10mm Auto. And I picked the only gun that seemed like a good idea for carry in 10mm, the Glock 29.
That was 6 years ago and I'm still carrying exactly that, and I'm still carrying it in the first decent (but extremely low cost) holster I found, a KHolster IWB... leather backed kydex. No-frills, for sure. It's been outrageously durable, though I believe if I tried a little harder in a holster, I might find some more comfort in carry. But I do fine with it.
And for spare mag? The ugly, "couldn't be cheaper" OEM Glock cheapie plastic rig.
Oh, and "philosophy" ? I'm a recreational shooter. I'm not a recreational gun-carrier. To me, that means I have one carry gun, and I carry it all the time. Chasing down the next carry gun, or giving everything I own some "carry time in the rotation" interests me zero.