I've been using this fo almost a year now so it's about time I added my long term findings I reckon.
PX Error - Quite possibly the scopes biggest downfall is it's so good, you can have your head in the wrong position and not notice. I don't think it's more prone to error than anything else I've used but I'm better at noticing this sort of thing now.
Cross Hairs - I lose the cross hair betwen 14 and 16 yards (I'm sad enough to measure!), I actually like it as I now to aim dead on. Not a problem more of a quirk,
Zero - I've not had to adjust this scope since January, unfortunately I thought it was off on a couple of occasions where I've been fooled by the wind. It always ends back up at the 0 marks from the start of the year though. Can't say fairer than that though.
All in all it's been awesome throughout whether HFT, Sporter FT or hunting. It's not a scope that can just be picked up and get along with right away as it does have some quirks that need learning however.
Ryan