The question is to compare Leupold and Conquest 6.5X20. Can't help you there, but I own both in 4.5X14. one is 50MM and the Zeiss is 44MM. It's really splitting hairs, but it seems like the Conquest is superior, optically. I think it's made in the States, as well? The Leupold is shorter.
I've had the Leupold for quite a few years, but seem to recall that it cost about $400(?) at the time. The Conquest was about $675, last year.
There are features besides apparent clarity, to consider, Warranty, engineering, durability, low light "brightness", reputation, and that gray area, American made (assembled)with Euro components or is it somewhere in Asia?
They are both decent, take your pick. LB