I am not experienced with Mark 5s, but my $2500 Mark 6 was little more than a paperweight. I own two of them. I have four friends with Mark 6s. Between us, five of our six went back to Leupold.
One of my two was fine from the get go and still works. The other took FOUR opportunities before Leupold got it to hold zero and somewhat track. In the course of getting it repaired, I was cussed at, called an incompetent idiot, so on and so forth. I was promised a new scope if they found it to be defective (which they did once they put it on a gun outside their lab——funny, scopes work in a lab but not in the field), but instead they repaired it and gave it a fresh set of ring marks where they mounted it. If THAT is the customer service Leupold has, I hope they go out of business.
My fiends that had them fail sold them as soon as they were repairs. I wish I had sold them, but I keep trying because the weight was important to me and at the time, nobody came close. Now I can't sell them for anywhere near what I have in them. Some heavy hitters suggest the Mark 5s and at this point I'd trade them for a set of Mark 5s since they are known to work. But that's a pipe dream and my days doing business with Leupold are over. I know $5,000 is nothing to you, but it's a lot of money to me.