I just recently picked up an S&B 5-25 and very impressed compared to the four NF 5-22s I have on my rifles. So thinking of slowly upgrading all my NFs to high end glass slowly. I was looking at the Kahles k624 particularly with the mil6 reticle which is a Horus looking reticle. I wanted to know how the Kahles stacks up against the S&B as far as glass clarity, features and ruggedness. All inputs appreciated.