EoTechs are good for close range CQB out to around 200m or so.
About the same with Aimpoints.
Bucks!
These depend on if you want a dot with a big circle around it, or just a dot.
Past that range and the dot covers too much of the target for fine applications even with a 3X flip or twist to side magnifier behind it.

The Leupold 2.5 scout scope on the top rail of a 20" barrel works very well for both close work and right on out to 300m.
Slightly less bucks

ACOGs are good for longer ranges and if your eyes can adapt to the Bindon Aiming Concept (mine apparently don't as I really can't use a ACOG that way) If your's can't as well, there is an attachment to stiock a Docter, or MRDS dot sight on top of the thing to give you close range aiming.

Major Bucks!

A 1 X 4 Schmidt & Bender variable on the top rail of a receiver works pretty good for everything out to around 300 as well.

Interstellar Bucks!

I've shot all of these and personally have Eotechs, Aimpoints and Leupolds on different rifles for different purposes (like clubs in a golf bag)

I can't say which you should have. Determine what you want to do the most with your AR, also try and hook up with people where you can try out the different optics out these to see what works best for your eyes. I have been blessed with the opportunties I have been given in the past few years to be able to do this.

ranges. Both are the best IMO for what they do, but neither are cheap.

Inside 50 yards, the Reflex is fast, easy to acquire, truly rugged, automatically adjusts to varying lighting conditions, always on, and never needs batteries. There's good reason why the boys in the Sand Box will trade two Eotechs for a Reflex.

For longer ranges (I've used them to 1000 yards), the ACOGs are just wonderful. The optics are exceptionally clear, the ballistic compensator is easy and intuitive to use, they also adjust automatically to various lighting conditions, are always on, and never need batteries.

Email me if you're looking for a Reflex. I have a couple extra for tradin'.

Leupold 1.5x5 on my LW plinker.
NF 5.5x22 on my coyote/varmint gun.
NF 8x32 on my 600yd match rifle.

Reddots are fine for kicking in doors and 3 gun games, I'm not doing either.

Keep the change...........

on & off. I have a couple of them and prefer them. They are tough. The combat Marines and one SEAL that have worked for me are happy with either one, with slight preferences for Eotech's wide field of view. I have a couple Eotechs: they are VERY quick, and easy to use, once the light is turned on.
I like Millet's 1x3 power Illuminated reticule, not sure yet how tough it is. I have one, it is on loan to a friend's son for coyote season.
I have a Leupold 1x3 etched reticule that can be illuminated as well. Other than the lack of quick release mounts and the dot being a bit large past 150 yards, I like it a lot. My personal favorite AR is a 14.5" DSA that I have a Aimpoint Mk3 one and a 3x aimpoint magnifier.

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Of the Troops & For the Troops

A Mepro 21 which works as well or better than any other reflex sight…. meaning it has all the down sides they all do. Dark window and washout problems. I got it cheap, I wouldn't buy another unless it was a real bargain. No way I would ever buy a new one. I like it better than the Trijicon one I had, but that's it. It works great for what I use it for though, recreational shooting in open well lit pits. (45 acp)

A Burris TAC-30 that's been bouncing back and forth between my .22 upper and my 6.5 Grendel upper. Decent glass for the price and a usable reticle. The illuminated reticle doesn't do me much good on this one personally. Not fully daytime visible all the time on the bright end. And I found hunting with it last week the lowest setting isn't dim enough to be real useful. The illumination control stinks, they did away with it an upgraded it on the newest model the MTAC (but it's like $100 more). 1 - 4 power. On 1x it's just like shooting an Eotech, sadly just not as bright.

On my "tac ops" rifle (Tactical Optics match rifle) I have a Mepota ZD. I can't say enough nice things about this scope. I love it. The glass is amazing. It's a true 1x (1-4x), fully daytime visible and dawn/dusk usable. Bullet drop compensator of three chevrons works real well for me. I had a Mepota K-Dot for a couple years which was a great scope, but out past 250-300 yards guessing and trying to remember hold over was tough with the reticle. I still love that scope and wish I still owned it on another rifle. I got lucky and got into that scope real cheap. A few years later I was able to upgrade for a small charge thanks to a little help from a factory rep (Meopta USA is near by). Even with the great first price and the great uprgrade… I still have more money in this scope than any two or three others scopes put together. It cost more than most of my guns. More than I paid for both my cars together… though that's misleading and not saying much. lol

to me. A better scope (I think) than the Colt 3x I had on my old SP1 carbine which was completely adequate.

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Sincerely,

Hobie

Honestly, I'm too cheap to buy really good optics on 'fun guns' but I have a pair of 1.5-5x Bruntons with what they call their turkey reticles. Basically an unlit version of an EOTech. It's very quick up close it can still bring farther targets much closer. My eyes never have been great so I like the magnification for any kind of precision.

For most up close work, a red dot works great. Aimpoints have amazing battery life and a simple reticle. The EoTech reticle can be very useful up close or at distance on e you unferstand it; some consider it 'busy' for ip close work.

I like some magnification for precise work at anything over 50 yards or so. That being said, I've got a micro red dot on an Ultimak rail on my 13" barreled AC556, and have had no trouble hitting a half scale IPSC target on the 100 yard range.

Then, on another AR, an 18" heaven barreled .223, I have a Nikon 4.5-14x scope and its wonderful glass. Fun for punching paper and hopefully for nailing some coyotes this winter!

It really depends on what you want the main use for the rifle to be for optics use. I think a low powered variable is a very versatile optic for a lot of different uses.

I like this one:

http://www.midwayusa.com/Product/315405/konus-m-30-tactical-rifle-scope-30mm-tube-15-6x...

I use my AR mostly for 3 gun. Except for one match this season, most shots were at 100 yards or less. This year, I plan to do some coyote hunting for the first time. I think 6x at 200 yards will be giving up something. This scope is clear and not over priced.
Mark

Three AR's with 3 different optics. One with a ACOG, one with an Aimpoint, and one with a Burris 1-4x MTAC scope. While the ACOG and Aimpoint are great, I find the Burris MTAC to be the most useful. It has an illuminated reticle, that at least on mine, works really well in daylight or at night, and is easily adjustable for brightness. Really well designed reticle that allows hits out to 500 yards, and shows red when illuminated and black when illumination is turned off. On 1x it is like using a red dot sight. On 4x it is like using an ACOG, but with a reticle that is more user friendly to me..... I don't think the MTAC is as rugged as an ACOG, but it's worked well for me so far and is a lot more friendly to the wallet.....

nm

We run Aimpoint CompM4s on rifles that are racked in patrol cars. I also own one CompM4 and an Aimpoint R-1. They've been pretty rugged and durable except that I've had to send two back for repair, only cost us the shipping.
The EOTech's used by SRT people died completely and were problematic when they worked. They've been replaced with Aimpoint's also.
I'd like to look more into low powered variables for my personal use, I've been considering that 1-3 Weaver that Hobie mentioned.

Eotech 516 , It works better than irons, only fast hits count! my ar is for defense . not for varmints at least small ones