The Burris XTRII is a superior optic to the Vortex. Clearer glass, truer color, less haze, especially at higher mag. I can see better at 20x with the XTRII than at 24x with the Vortex.

Mil for sure. The SCR reticles http://www.burrisoptics.com/reticles/scr-mil are awesome. I'd suggest you look at the 4-20 as it is about perfect and you will rarely even use 20x.