I want to get one but can't make up my mind. For a Colt 6721 AR15A3
Eo-tech is hands down the best for CQB. If any shooting is to be done at any distance greater than 50yds then the Acog(TA31RCO US Military version)would be the choice.
I can not afford either , but have fantisized over the Acog on many occasions. The Acog is the better all around optic. Use the Acog for distances farther than 50, and you can use your iron sites less than fifty. Hell if you really want to trick your colt out put a laser site for 0-50 yards, and use your Acog for beyond. I put a laser on my DPMS for that same distance, and a man size target is toast at fifty yards. I use my scope for farther shots. I would recommend getting a either a laser that will shoot both red and green beam, but off the two I prefer the green for visibilty.
no doubt... I have a 2X ACOG on my M4. it works great for CQB and longer shots. it will cost you though. mine was about a grand.
EO Tech shuts off automatically after four or eight hours, depending on how you turn it on. This can't be deprogrammed. If you need a gun at a moment's notice, forget the EO Tech. Two of us had the model 552 on my last deloyment, and both of them went tits up after about six months. Maybe this is a fluke, but I doubt it. I sent mine back to L3 (after two weeks of trying to contact the warranty rep) and they fixed it, but the message is clear; the sight is not rugged at all, the battery life sucks, the automatic shutoff is a pain in the ass, and customer service sucks. ACOG is a great sight, but my preference is the Aimpoint.
I have had an EoTech for about 3 years and have never had any problems. Mine has never turned off either. A buddy of mine turned it on forgot to turn it off. I checked on it the next day, and it was still on. The night vision works great as well.
There is a new train of thought for CQB. I can not remember his name, but there is an instructor teaching 1-4X variable power scope usage. For CQB the scope is on 1 power. If the enemy needs to be engaged at distance, the scope can be maxed out at 4x power. This was thought up as an answer to a problem reported on the ACOG. The reticle was covering the target at 200 meters. With the 1-4X scope, the reticle would stay the same size in relation to the target. I have not taken the course, I know someone that has, he was really impressed and put the scope on his M4.
and after talking with Army, Navy and Marines here in Kuwait...they all love the ACOG...of course, you are going to pay for it. If money is not an issue, that seems like the consensus from the troops I have encountered. Of course, I have met 1 or 2 who don't like the ACOG, but those were definitely a small minority. I purchased the Aimpoint...also seems to have pretty favorable reviews.
But trying to engage a bad guy from a moving HMMWV with a magnified sight is not effective. It's not easy with a red dot sight like an EO tech or Aimpoint, but it's possible. That may not be a big issue in the states, but you never know.
ACOG only because I had one on my M4 while in the military. Never used the EO