i read the article above about selecting an optic, have pretty much decided on the Comp M3.  (Can't figure out what the M4 does that makes it worth so much more money.  Maybe you can advise.)

Anyhoo -- which, in your opinion, is the best for general purpose urban SHTFTEOTWAWKIOMGWTFBBQ carbine, 2moa dot or 4moa dot?  (16" LW Colt flat top upper on Cav Arms lower).

Denkyouberrymuch.

Dear Milquetoast,

You ask a question of preference. Neither is "best." I'd recommend going into a gunstore (like Scottsdale Gun Club) and looking through both.

COMP M4 comes with mount already attached. By the time you add another $125 for the mount for the Comp3, the price between the two is a lot closer.

A 2 MOA dot can be bloomed to make it much larger (4 MOA size). Either would be fine for shooting within reasonable ranges (~300 yards or less).

Nearly all my shooting is 100m or less so I prefer the quicker-to-acquire 4moa which also stands out better against bright backgrounds. By turning down the intensity a click or two I get a much smaller dot for more precise shooting. However, if I were going to use a magnifier then I would go w/the 2moa.
Tomac

Thanks.  This is all good info.
Has anybody ever done a side-by-side with 2moa and 4moa to see if there is a measurable difference in target acquisition speed (using an electronic timer), or a difference in slow-fire group size at 100 or 200?  I would think the 3-gun competitors would have worked this out to 5 decimal places.

Quoted: Thanks.  This is all good info. Has anybody ever done a side-by-side with 2moa and 4moa to see if there is a measurable difference in target acquisition speed (using an electronic timer), or a difference in slow-fire group size at 100 or 200?  I would think the 3-gun competitors would have worked this out to 5 decimal places.

I have both.

While I've never conducted a scientific test on them, I would say that they are both fast on target.  Obviously, the 4MOA will be faster, but will cover more of your target at range.  I tend not to set the dot at its highest setting anyway (on the 4MOA) so it becomes closer to the 2MOA.

I also have both models (2moa / 4moa dot) and a magnifier.

I much prefer the 2moa dot when shooting over 100 yards. Less than 100 yards the 4moa dot is just fine but as others have said, it's easy to make a 2moa dot a 4moa dot (just turn up the intensity a little).

If you are going to also run a magnifier get the 2 MOA...If you are looking for CQB speed the 4 MOA

I have had them both...liked the 2 MOA on the 22 LR for a little more accuracy on birds and squirrel heads..

But since the Micro Aimpoints have come out...I am switching over...

We ran an Aimpoint magnifier behind a Micro at the range and a Comp3 2MOA ..I can't really tell much of a difference
to tell you the truth...other folks mileage may vary...

Got Micros on the ARs my wife's 10/22 compact and the 870

Just got one for our nephew's new rifle for graduation from Marine Corps boot camp

Our other nephew is oggling one of mine...so we might make a swap ...if so I will sell that one and buy
another Micro..

Oh, great.  I had just about decided, and now I have to go read up on Micros!

I have been perfectly happy with my 2 MOA M3 for the past few years, but recently got a pair of 4 MOA T-1's.  While I haven't had the chance to run them very much yet, I am starting to like the larger dot better; here's why:  My right eye has astigmatism.  The brighter the intensity is set, the more pronounced the astigmatism effect is.  It seems qualitatively that the intensity can be set slightly lower with the 4 MOA for a given environmental lighting condition, thus the effect is minimized.  YMMV, depending on the condition of YOUR eyes.

That being said, I will start wearing prescription eyeglasses for the first time in my life next week when they arrive, so my opinion could quite likely change with corrected vision available as an option.

I don't tend to use the AP's for anything other than close range [<100m] and I never use a magnifier, as I have other options available such as ACOG and NF on QD mounts for longer range/greater precision scenarios.

All of the options which you are considering are good ones IMHO, but yes, you should definitely check out the T-1's.  They are 1/2 pound lighter with a mount than the M-series.  Also, several folks have reported that the "4MOA" dot of the T-1 does not appear to be twice as large as the "2MOA" dot of the M, and I am inclined to agree from side-to-side comparison.

Would you mind elaborating further on the math behind the diode/tube/dot size relationship?  This is most interesting.

I've been a big advocate of the 4MOA for a loong time..
In my experience it's a better tool for what an Aimpoint does best..

Yea, I know the magnifier crowd will tell me you need a 2MOA, and If I were using a magnifier, I would ...
But I don't use one and won't be getting one. The Aimpoint is a CQB optic and I'm not going to try and turn it into something different then what it is...

The Dot on a  T-1 Aimpoint is actually a little less then 4MOA and when turned down, gives a very precise aiming point.
The dots on M2's etc can be turned done and allow very good hits out to 300meters if you are capable.

and for a General purpose urban SHTFTEOTWAWKIOMGWTFBBQ Carbine as the original poster described... the 4MOA is what you want.

Quoted: I would love to elaborate more, if I could remember that type of math I was going off of the word of Freddie Blish, Aimpoint's Military rep. Will see if I can find the write up he told us to look at to explain it. Nate

Nate, I would most appreciate if you could locate the details, as I suspect others will as well.  Sorry if it sounded as though I was implying you were incorrect; that was not my intention at all.  Inquiring minds need to know.  

Thank you all for your help.  Based on what I learned here, I just ordered an Aimpoint ML3 4moa.

Now wouldn't it be great if Aimpoint brought out one with a switchable 2moa and 4moa dot?

That would be awesome!