Had the 4-16 zd, and regret selling it, I just didn't like the AO for hunting purposes. But damn the glass was amazing, tracked perfect and it just felt like a real quality scope. I'm no glass/scope expert, but I'm already looking at buying another. The details you could pick up at long range was unreal, and in twilight, it has equally unreal. I remember watching a big buck at 25 mins after sunset, in highly over cast skies. With my naked eyes at I think it was 300 yards, I could just make out the outline of the buck, and could barely see it's antlers. When I looked through the scope, it gave me a sense of almost having night vision. I kept looking out of the scope and back through it, and was honestly wowed... But I''m probably not the guy to answer this, as I've only briefly looked through any other high end scopes. But I did a lot of research before I bought it, and a lot of others experienced guys on here, and other places did say it had glass equal, or close to the Zeiss Victory line. And Isn't the diavari a lower end Zeiss? Heard equally good things about the 6-24.
Only negative for me was the AO, and in hindsight it wasn't that bad. I highly regret selling it. Hope someone else comes along and gives you more info, but imo they are a hell of a great scope. And I'm hopefully gonna have another one, might go for the 6-24 for my target rifle for long range coyotes.