As far as the butt stock shell holder and a few things I like about it...
I like how the leather feels against my cheek when shooting, better than the stock alone.
It also acts as a minor shim to raise my cheek weld a bit for better scope alignment.
Also as
@Tanks mentioned, it is convenient to carry ammo there.
For speedy reloads, I'm shooting a Blaser R8...arguably the fastest bolt action available.
With 3+1 available in the firearm, I should be more than reasonably safe for initial contact.
With the PH and Mrs BeeMaa and their fully loaded firepower...backup is covered as well.
Yes, I understand tactical magazine reloads and running & reloading...etc.
But I seriously doubt the difference between a belt and stock ammo carrier is gonna make a hill of beans difference.
If the SHTF, I won't be thinking "man, I sure wish I had a belt mounted carrier instead of this stupid stock thing".
More likely is my PH calling me a dumbass for making a crap first shot.
As for the aesthetics of it...well let's just say that not everyone is a fan.
And thats OK as well.
Maybe if it was all leather it would be better?
I have a Galco Safari Five belt ammo carrier I used on my last safari.
Having all our cartridges based on the 375H&H makes it an easy fit for all.
And I'm considering cutting the top flap and bottom latch off to make it an open top.
Mrs BeeMaa has shown an interest in using it, but doesn't want to maul the beautiful leather.
If I do go with another belt style, I prefer the belt with loops already installed.
Having a complete rig like
@Red Leg is very tempting.
The open top belt slide would be the other option I'm considering.
My go to leather would be Dick Murray.
His leather goods are amazing and very reasonably priced.