I used the Kahles 10x42's for a couple of years and had no problems. They saw some pretty hard use. Ran across a good deal on Swaro EL 10x42's and sold the Kahles. The EL's perform significantly better but the Kahles is a better value in my opinion. As far as durability, they both are excellent. Don't think you can go wrong with them unless you are expecting top tier performance.

Hope this helps.