I am an enormous fan of the 7-35, but damn good glass is addictive. I want a ZCO too.Agreed my 7-35 is super picky past like 27x. I agree the high mag is part of it but at 25x it's still noticeably tighter than say a schmidt or gen 2 razor. Was just wondering as I find it to be a pretty important quality for a PRS scope with my style of shooting. The 5-27 seemed to have a decent enough eyebox from the time I've spent with it so that's good to hear the 4-20 is similar.