It isn’t always about being able to shoot tight groups, combat optics usually have some level of magnification because identifying a friendly from a foe is of the utmost importance.   A few friends of mine liked the ACOGS because they helped them identify wires from IED’s from out to 100yds.   IF you had zero magnification you might have trouble knowing from under 25yds away and that is not safe.  The Eotech 3x magnifier gives you this ability but you will have to worry about having two mounted optics  on your gun and not one which is basically what the Trijicon ACOG is.

If you want to get a really good deal on a Trijicon ACOGS, you’ll probable have to buy a used one from someone having a baby or someone getting out of the military.  Those Trijicon rifle scopes aren’t cheap, but they will hold up and they have a proven track record of doing so.  I have yet to hear of anyone having mounting issues because in my opinion it’s impossible to mount an ACOG wrong unless you use a hammer. There are big differences between each Trijicon ACOG reticle and it’s your job to decide on which style of reticle fits your needs, but always be open to adapting.