I never realized just how small of an objective lens the micros have until I started shooting my scoped AR more.

I'll agree with GOST that putting it closer to your face helps you pick it up quicker and will also helps reduce the parallax that red dots can have.
As far as height, if you're not running a fixed front sight I'd say go with an absolute mount, if you're going with a fixed front sight go with lower 1/3.

Since you don't go cheap, get the best QD mount you can.

Those are my $0.02. Which probably isn't even worth that since I am not nor have I ever been an operator.