I have a 6-25x56, 30mm tube, with mildot reticle on my 300WM. This scope has 70 moa of elevation, and from my 500yd zero I can poke holes in stuff out to 1600yds.
I have never had a problem with mine, but my gunsmith was talking to their rep one day, and he confessed that several of the 6-25x56s got out the door missing a part. Those were locking up the ao as well. Most of those were recalled before they were sold, at least around here. I had to wait for 3 mos for more to come in. Other than that, the only other thing I ever saw, bad that is, out of them, is some of the zoom rings are quite stiff to operate.
They have a bit of curvature of field, right at the very edges, I wouldn't put them head to head with a $1000 leupold, but I don't think you can beat them in the price range.
As the gentleman who posted before me mentioned, even if you have trouble they will replace it.
Its a heavy sucker, but for a piece of glass this size, arent they all?