I have the Vortex Diamondabck 4-12x44 with BDC reticle. Absolutely love it....
The reticle matches my 75 gr BTHP handloads at 2700 fps from my 16" RRA to 500 yds perfectly. I think the reticle may have been changed now, but mine is as follows.
+ = Zero
dot 1 = 1.5 MOA
dot 2 = 4.5 MOA
dot 3 = 7.5 MOOA
dot 4 = 11 MOA
The turrets dial spot on as well to get me to 750, and the box test I did when I first got it was spot on. In all honesty though, I do not dial my turrets often on that scope, so I cannot speak to the hardiness of the mechanical parts. It mostly doesn't go past 500.
IMO, You cannot go wrong spending money on Vortex Optics
. I have a bolt gun at the smith now, and when it gets home she will get a Vortex of some flavor.