The Monarch is a great scope (i've had two), as far as glass goes they are superb, repeatability has been good, but, IMHO the eye relief of my two 6.5-20's was.... for a lack of a better term, terrible. On my heavy varmint rigs they worked ok but I'm pretty sure they wouldn't find their way onto a large caliber magnum. Go to your local dealer & play with a few before making your decision is all that i'm recommending, please don't think i'm trying to talk you out of it, just sharing experience.
The mil-dot system works, it depends on how far you plan to shoot; if you aren't going to stretch it out 500+ don't bother, it looks cool but isn't really needed IMHO. The BDC reticles are ok as well but can be difficult calibrating the power ring to your particular cartridge (my experience). I have been buying the regular Duplex reticle & dialing the needed MOA, that way I KNOW my hold matches my drop (as long as I do my part)