I have the NXS 5.5-22x56mm on my .50, been there for over a decade and hasn't had a problem. My problem is NF is coming out with their new NXS scope called the ATACR and another called the B.E.A.S.T. and I would like to upgrade. Awesome scopes, with a 50 MOA base I can get out over a mile with my .50 and its awesome to be able to do it.
Enjoy the scope, they're great pieces of machinery and will last a lifetime.