I have the IOR 2.5-10x 42mm with illuminated MP8 reticle in the 1st optical plane. I could not be more pleased. Boxing the scope at 400 yds was perfect. Return to zero is perfect. Optical quality is better than 10x 40mm Leupold in any lighting conditions. Total rd count on my rifle exceeds 4000 and this scope was on for aprox half.
I also had the 16x 42mm but a buddy wanted it bad and quick for a trip west. His 16x Leupold had just died as he was preparing for the get-together. The IOR is the 4th scope that rifle has worn. Weaver 4.5-14 mil dot Tactical, Nightforce variable (I think something like 6-22x), and Leupold 16x and none have survived to 500 rds. The IOR is currently up to 370 rds on that rifle, after aprox 2000 rds on my .300 WSM