I own the Crossbreed Supertuck, which is similar in design to the Comp-Tac Minotaur Mtac and Minotaur Spartan holsters, in that they are all composed of a kydex shell with a leather backing/body shield.
For the general design, I can't really speak much for holster wear on the gun's finish, as my carry has a stainless slide and plastic frame, so there really isn't any finish to wear. I know people who carry other guns in the Supertuck, and there is some wear, but not much. A little holster wear usually isn't a big deal at all, and can be aesthetically pleasing and proud sign of honest "wear and tear" of the gun. As long as you clean the gun regularly, and maybe wipe it down before putting it away at night, no worries.
I've been very pleased with my Crossbreed Supertuck. Very concealable and very comfortable. The two Comp-Tac Minotaur designs should carry just as well, as the designe is fairly similar. I believe the Minotaur Mtac has better quality and finished leather, as well as a backing to cover the rivets. The Minotaur Spartan is significantly cheaper than the Mtac, without anything covering the rivets. However, my Supertuck has exposed rivets, and they are a complete non-issue. I've read reports of the same with the Spartan. If they do happen to bother you, a lot of people just by some moleskin to cover the rivets.
If I had to buy now, I may consider the Spartan. The Minotaurs have the added advantage of being able to buy kydex shells for different guns that can be easily swapped out if you have more than one carry gun, and I think they're only about $30. That, and there have been some price changes since I bought my Supertuck, and the Spartan is now just a wee bit less expensive than the Supertuck.
That being said, I've had tremendous customer support from Crossbreed. They have a lifetime warranty on their holsters, and a 2-week free trial period. Comp-Tac only has a one year warranty on their products, I believe.
I'm not sure if going to a store to check these holsters out is a viable option, as they are essentially semi-custom pieces. I was lucky enough to know someone with a Crossbreed, so I could give it a go.
Not a pretty piece, like the custom leather that's available these days, but I've always been one for function over form, and the thing WORKS and works beautifully.
-JT