I want to have more versatility than a red dot on this rifle.  



I'm leaning towards an ACOG.  I believe I've narrowed it down to either the 3.5 X 35 TA-11 with the green horseshoe, or the 4 X 32 TA31RCO with the green chevron.

I have two 10.3" SBR's, so this wouldn't be first and foremost an up close and personal rifle.  But then again, if it's what I have at the time it could be.

I like the increased eye relief of the TA-11.  That's a huge plus in my book.  I just wonder if there is a perceivable difference between the 4x and the 3.5x.  I don't think so but I'm not sure.  The TA-11's reticle looks, on a computer screen anyway, more precise and still highly visible for close-in work.

I'm looking for some information and advice from those with experience with them.

Thanks!

I own the 11 and used 31 on a friends rifle. No, there is not enough power difference to matter. The fov is better on the 31 but the eye relief is better on the 11.  Having used them both, I wouldn't buy a 31.

I recently was in this situation, choosing between the 2 models.

The .5 magnification difference wasn't enough to out weight the eye relief issue. I've been very happy with my TA-11f.

Between those two, TA11.

There isn't a big difference in magnification but the fov is better on the 31. Here's a gif for comparison:

I've owned both, I still have the TA11. To iterate others' comments, the sacrifice in FOV and weight of the TA11 is worth it over the TA31's ER in my opinion.

I guess I'll take up for the 31, here's my thoughts as an owner of multiple examples of 33/31/11s. I love TA-11s, they have a very forgiving eyebox/eye relief and make picking up a sight picture very fast. Yet when I think of the 31, it is lighter, smaller, (very slightly) higher magnification, better FOV (though to be fair it also takes up a proportionate amount of visual space so this is largely moot, see above pic).

If you shoot NTCH, I'd consider the eye relief moot as the 31 is perfect for this. If you don't, or are shooting a larger rifle (my Scar 17 uses a 11 to avoid scope-eye), I'd recommend the 11. There is no 'best', just best for you. Having said that, for NTCH AR-15s, the positives of the 31 far outweigh the lesser eye relief *for me*, and I say that as a owner/fan of both as well as the 33.

As others have said, it's a trade-off: TA31's smaller size/weight and larger FOV vs TA11's eye relief. Compared to those, the magnification difference isn't really a big factor.