I just bought two. Mounted them both on .338 Win. Mags. The guy I bought them from swears by them and says he can't keep in stock and can't get new stock. I'll let you know how well they hold up. I'm going out next weekend and burn some powder.
I took them out yesterday and burned some powder. Great eye relief. Clear out to 300 yards. We'll see how they hold up under the pounding of the .338 Win. Mag.