I had two of the X5 3-18x50 (non-illuminated), one of them had the 4WX reticle and the other had the BRM reticle. The one with the BRM reticle had to go back to Swaro for failure. It stopped tracking/adjusting properly and stopped holding zero. That particular scope/rifle was a safe queen. The one with the 4WX reticle saw heavier use and minor inadvertent abuse and never had any issues. Ultimately I swapped them out for FFP mil/mil scopes. If all you care about is glass/low-light performance there isn't a scope I've looked through that performs better (anything Leupold, Tangent Theta, Nightforce ATACR included; never seen a ZCO to compare though). If you want them to be reliable and durable, well one of my 2 failed. However, I'm pretty sure
@Ryan Avery has used/abused the X5 and could give you a better durability/reliability eval than me.