Just visited Athlon HQ and got to play around with this one.
I find the difference between the 34mm Midas Tac and ETR to be very very slim. Maybe I just don't have the eye for better glass, but, I failed to notice much of a discernable difference. Makes illumination the biggest difference between the two.
Once I get rid of my Gen1 Ares BTR's (They're MOA, floating crosshair) I'll be hunting out some 34mm Midas Tac's (Mil, Floating Dot) for my centerfire rifles, and likely the matching 30mm Midas Tac's for rimfires to finally make the switch to Mils.