I have a vortex viper 2.5x10x44 with a 30mm tube mounted on a Larue upper. Like I said previously, this is a great scope. Its not as nice as my leopold mk4, but I dont see $900 diffrence between the two either. I was in your situation recently. I compared the leopold mark ar, nikon m223; I chose vortex because their selection, price, and quality were outstanding not to mention the fact that they probably have the best warranty in the business.