I just got home an hour ago from work and in my mailbox was my delivery from Brownells with my brand new MagPul Terrains. I hadn't even removed all the plastic off the sunglasses and I noticed the huge scratch on the lenses. At first I thought is was a silicon grease smudge so I tried to wash them with some dish soap, but no, it was a huge abrasion on the outer lens.
I am a huge sunglasses fan and I have owned ALL the popular brands. I have become sick of Oakleys prices and horrible service after the sale. So I thought I would give MagPul a try. First off, I am not overly impressed with the quality vs. price. I did get a good deal from Brownells, but they shipped them out on a postal mule. But that's a whole different set of gripes.
I am going to go through Brownells for a refund or exchange, I need some gun parts anyway. But I would HIGHLY caution anyone looking to try these sunglasses. As OP stated the scratch resistance is lacking. I know they meet a level of protection for impact from flying objects, but that doesn't do anything for the ability to resist scratches. These are very expensive sunglasses for the quality you get.
For what it's worth, I do like MagPul's products and their company and will continue to buy most of their products.
You can see the abrasion at about a 45 degree angle on the lens.