I'd be careful about buying a new leather shoulder rig like the Galco Miami Classic II or a Bianchi X15. They are well made but in an outdoor or field environment they may wear out or break quickly.
Synthetic or treated materials would do better IMO. Sunlight, sweat, rain, snow might damage some holsters.
The UM92 or STU styles hold up to field use.
Clyde
Let me start by saying it is hard to understand the "tone" of someones voice with the written word...so to be upfront, I writing this with a friendly, somewhat "ribbing" tone
and I mean no disrespect to you Clyde...so I'll add the smiles now.
What??? Thats not and opinion, that's just wrong information.
Leather is absolutley better than any plastic crap...It is a tried and true American product. It breathes and wicks moisture from you skin, instead of trapping it like plastic or nylon.
When testing the durability of a specific leather for a holster harness, I put it on under a backpack. 3 days per week, from July until Oct 22nd, I used this harness without ever applying any oil or conditioner of any kind to it. On many summer days it was totally saturated with sweat and it turned white from all the salt stains...but it NEVER got hard or brittle. It always dried over night.
These were not little trail day hikes, but true 3 day mountian trips into the high country....I actually slept in my holster several nights when I slept above treeline because the Grizzlies were hanging out in the rockslides.
The one thing I really noticed was that, even after the leather became totally saturated with sweat, it never felt grose or clinging...just seemed to feel like a part of you. I guess it was way the leather breathed and pulled sweat from your body and evaporated it to the air that made it feel like part of your skin.
When exposed to sunlight I have no doubt the plastic will start to crumble way before the leather even gets to it's darkest shade. Leather will just suntan.
You can park your butt in a saddle for 20 years, ride it through every rainstorm, snowstorm, sandstorm and leave it on a tree limb for the nights...and then try to tell me. Leather is not suitable for "Outdoor Environments"