Have you ever used a magnifier with a EOtech or other Red-Dot?
I know because we see them in movies and magazines and Call of Duty they are a must have...
I would try it before you buy it however. I was going to buy the EO-tech one until I tried it at work and realized I had no need for it. Wasn't my flavor, neither was an ACOG.
I find that with my AR's I have them set up mostly with EOtechs or Trijicon Reflex's and I don't find myself shooting much further than 300yards with one, which is perfectly doable with a red dot or Iron sights, any thing further in distance I wouldn't generally choose one of my AR's.
Depending on the type of accuracy you wish to accomplish, your ammo choices... barrel length and twist, you can generally use the same zero in an AR platform to make hits from 0-300 yards on a man sized target. The 1MOA dot in my EOtech is perfect for this, and I use a 14.5'' barrel with a 1:7 twist.
Not trying to knock your choice, just suggesting you try it however, I am glad I did before I bought one because I did not like it.