Chunkychuck wrote:"Horsehide is a denser and tighter grained flesh than cowhide. This results in it being more moisture resistant. "
I was told by a couple holster makers the above same thing.
Gary Brommeland of Brommland Gunleather says that he prefer cowhide because it is not as dense as horsehide which allows the stitching on a holster to pull into it. He believes that protects the stitching because it is pulled into the leather instead of riding on the surface which makes the stitching more vulnerable to wear and abrasion.
I think the big plus of horsehide is probably it being more moisture resistant. But then in today's world, I don't know why there isn't some kind of chemical treatment that can be applied to exceed horsehide's natural moisture resistant.