I have the XS Ghost Ring and another company's front post. I can't remember who makes my front post, but I wanted a narrower front post than the XS system came with. It may not be as fast as the wide post, but it offers a little more accuracy.
I really like the XS sights. I have a XS scout mount, but I have not put it on a gun yet. I installed the ghost ring and liked it so much I decided to not use a scope. Now I am looking for a .357 marlin to put the scout mount on.