I have a Bushie mag with the marlube finish and it feels nice and slick. It seems to take slight scratching damage without showing too badly. I think if it took a nasty fall it would show worse then the GI mags.
I have a bunch of the normal GI ones with the dry film and they feel rougher to the touch and scratch very easily. I beat the crap out of them and they still look decent because the scratches are almost the same color as the finish.
I think the black marlube mags looks better but I am not sure if there is any benefit operationally.
My TAP rounds are loaded in the nice pretty back mag in my closet though.
As much as I would hate to spend the money on the HK mag I am tempted to buy one just to load some HD ammo in it.
I recently purchased 10 P-mags , these are my go to mags, but they are more ammo length sensitive than the C-Products mags if you reload. But with SAMMI length ammo they are flawless and alot more durable than any GI mag or even the H&K's. A really nice piece of work.