Don't know the Nightforce, but my ACOG that was issued, was already beat up, and spent 7 months in Afghanistan did great.  It endured being submerged in numerous canal crossings, numerous firefights, being banged up, and even kept it's zero after a 20 lb IED went off ten feet from it while I was carrying it.  I've done real world testing and the ACOG is superb.  I don't have one of my own because I don't feel like spending that cash, but it's a great sight.

Can't argue with that.

I had a TA31F, sold it for some other project. Definitely regret it now. If I ever get around to my next build, an M16A4gery, I'll be topping it off with an ACOG.

 
Finally, someone said it. Sure, the TA31 has a short eye relief, but that gives you tremendous FOV. The TA33 is fine for shooting at a single known static target, but the soda-straw-like-FOV severely limits its usefulness for me. I bought one after all the positive review here but quickly sold it after its abysmal performance trying to engage multiple targets and trying to scan for targets.


 

OP, the ACOG's biggest strength is size/weight to performance ratio. LPVs are plenty useful if you can afford the extra weight and size.

Acogs are super durable, our m4-s and cogs get beat to shit and ive yet to have a single unit not hold its zero or otherwise malfunction. We have some really old ta01s from the early 90's the the guys are still using even though the lamp is dead.

When shooting irons I always like giving myself the widest view through the small aperture which involved using the NTCH hold, so it's easy to deal with the TA31/01

You were using the TA33 wrong. It has to be used like a red dot and mounted far forward. You scan with your eyes not the optic. It takes alot of practice to get used to.

 
The FOV is what I love about my TA31, the eye relief is not so bad once you get use to it.


 

 
The TA33 is supposed to be mounted with the proper eye relief like any other optic. The whole point of scanning through the optic is to look for targets you can't see with your unmagnified eyes.


Even if you know where additional targets already are, a wide enough FOV like the TA31 allows you go snap straight to them which is faster than coming in and out of the optic. You can try this yourself by placing multiple targets about 50 yards away with several yards between them using a shot timer to measure how long it takes to engage them all with each optic. The TA33 is the slowest optic I've ever tried due to the small FOV.

"I have fixed stocks on many of my rifles and nose to charging handle isn't going to cut it in the standing position.'

I'm using an M16A1 stock on my carbine with ACOG TA01. This allows me to get pretty close to NOCH when standing, but honestly a collapsible stock makes more sense considering different thicknesses of clothing and other variables. But, the standard rifle buffer and spring work really well on the 16" middy with M16 bolt carrier - exceptionally smooth cycling and low recoil allow me to stay on target during a string of fire, so I'm not about to change the slightest thing on this one. This set-up just sort of happened over a short period and turned out to be a great shooter. I guess I'm getting a little superstitious in my old age because I've gotten to the point where I treat machinery like living things - like it is what it is, and if that's good, you keep it. If its bad, you start over.
The TA01 ACOG is a big part of what this carbine became, and I intended to use it all along. I've messed around with all kinds of combat scopes and I just said that's it, I'm getting the real thing. Its been a few years now and I haven't regretted it at all. I got a deal on a new one because it was the simple TA01 with no fiber optics or other extras.
You simply have more with an ACOG, like the serial number, the warranty, the service, the reputation and the experience of something like 25 years of combat use in some of the world's worst hell-holes. And of course you pay more. So I say the ACOG is still worth it. It just seems to me to be the ultimate combat scope to use on an AR15. I have another carbine, a Colt, and I just put another Trijicon sight on it - an MRO. I sighted it in day before yesterday and shot a 1" group at 50 yds with it using PPU 69gr Match (1:9 barrel).
To me Trijicon is still the only 'professional grade' combat scopes/sights maker.

I agree with RustedAce on this

It's good glass for the application.  Would it be appropriate in a 5-25?  No, but in 1.5-4x it's exceptionally clear.

I use the TA33 with both eyes open as well, just like a RDS.  It's nearly as quick as a RDS.

 
I never close an eye to shoot, and that does not work for me at all. To be fair I have goofy eye dominance issues, so it could be a personal problem.

this debate on ACOG's with the wide FOV vs the tight FOV is very interesting. i've been wanting to get a TA44 for awhile but there is also the TA45 with the tighter FOV.

i have a leupy mark 4 1.5-5x and shoot it alot on 1.5x and that FOV is quite large like the TA44, TA33 and i have become accustom to it but now the comment of "getting sucked in" with the large FOV makes sense.

now i need to go back and re-evaluate the plan.....thanks for the opinions. sounds like alot of personal preference.

Some good stuff in here.  I'm no closer to knowing if I would try one though.  Way too many options I don't know where to begin.  

It would be good if you could try a few.  I had the TA33 and sold it.  I like the TA11 best.  It is all personal preference.  No real right or wrong answer.

Definitely would help.  Don't know anyone with one and nearest shops that carry multiple models are a long ways away.

I read this thread and saw that many posters say the glass is bright and clear but may not compare to super high end optics.  But ACOGs have been around forever it seems and optics have generally improved quite a bit over the last decade.  Does the clarity match up with newer optics like the HD Vortex line for example?  Has Trijicon updated its glass?  I wasn't overly impressed with an Accupoint I used.

I think their TR24 AccuPoint line and ACOG lines have similar glass, to my eyes.
Their AccuPowers have better glass, IMO.

How is the tao1nsn?  Local shop has one.

Love mine. Favorite acog I've owned (owned a few)

I enjoyed the fiber optic part of my accupoint so was bummed to see that particular model doesn't have it, not a big deal to you I assume?

IMO its more of a short range precision scope. the cool thing is the back irons on top or get an RMR. i just cant use one anyone due to agin eyes, i cant see the ranging lines well enough.

Yes. Worth every penny.

DSC_7459 by The Dorsal Fin, on Flickr

yes

Im really liking mine.  First one too!

Have had my TA31RCO-M150CP for years...  Just got it back from Trijicon with new tritium pellet, and new fiber optic insert...

https://www.trijicon.com/na_en/products/product3.php?pid=TA31RCO-M150CP

Won't trade, sell, or give away...  Serious tool, for serious work...

How much $$$ did this upgrade/replacement work cost?

And how long was the turn around time?

Nope, not to me. The black lines stand out plenty clear for daylight shooting. It's a great optic.

I bought a TA 31 prior to deploying.  It was directly responsible for getting every member of my team back alive.  I'm not saying I couldn't have made the shots with a CCO or XYZ optic or even iron sights, but I didn't even have to think with it.  But that scope was the best $850 I ever spent.

I'm trying to find a source but the Marine Corps commandant supposedly said, "The ACOG is the best thing to happen to a Marine and his rifle."  Don't flame me if its false, I KNOW I read this somewhere

(I have zero experience with other brands other than aimpoint and EOtech so my opinion is skewed and probably irrelevant when considering your original question)

It's built very tough. No variable will be as tough.

You can drive nails with it, it seems.

The bad: The tritium element has a limited lifespan and not cost-effective to replace.

Prefer it over the fiber optic.

Doesn't bloom in the sun (I've used tape over the fiber) and is more precise. The tritium (mine has green oddly enough) is bright at night. With white light they all wash out and turn black at night.

It's the shit for 100-500y plates if you need a small package. I replaced a vortex PST with it to cut weight on my 12.5