Somewhere on here are links to demigod, llc. This is Zak Smith's site. Dude wrote up a great deal on the types of scopes available to the marksman including MOA adjustments or Mil adjustments etc. There is a wealth of information.
I am just a casual plinker for longer ranges, and nowhere near Zak or Hoser's level. However, I have found the IOR scopes to be a good value, with Schott (sic?) glass (used in the other high dollar scopes) clarity has to be seen to be appreciated.
I bought the straight 6x "tactical" scope with the M9(?) reticle with the 1/2 Mil markings. It is a magnificent scope. The outside of the scope is sort of primitive, but the optics and the adjustments are top notch.