Last year I used an Extreme sight and was extremely disappointed in the durability. The fiberoptics broke very easily. It was a pain in the ass stopping in the middle of the mountains in Alberta to rethread them. Other than the durability, they were great. In fact, now that they made some changes and put in some new guards and supports for the fiberoptics, I put on on my new Katera. We'll see how it holds up this fall.