I've looked at both TA31 and TA01, and I am still devided between which one I like better.

Many people seem to prefer TA31 for its BAC feature, but does anyone actually like TA01 (NSN) better?

It seems like fiber optic tube on TA31 looks fragile, and I heard that long range sighting is more difficult with TA31

The fiber optic tube you see on top really isnt the fiber optic. The fiber optic is actually the colored material you see inside of the more or less clear housing on the outside and it is anything but fragile. The clear housing can crack or chip without having an effect on the optic at all.

The reticle on the TA01 series is finer and easier to use for pin point precision shots than the larger and simpler reticle in the TA11/TA31 series. But it is precisely the fine reticle of the TA01 series optics that most people dislike. The reticle is too fine for most anything else other than precision shooting.

And to be honest, your trigger/barrel/ammo combo will very likely do more to inhibit you from acheiving the fine accuracy the cross hair reticle is capable of anyway.

Overall, the TA11/TA31 series is just a much more useful optic than the TA01 series. The TA01 is very good for what it does, the problem is what it does is so much more limited than the TA31/TA11 series. So figuring out what you want your rifle to do best will help you decide which optic between them will best suit your needs.

I'd also add that at the ranges where a fine crosshair is actually useful (400m+), the TA31 uses a fine crosshair.

Also, don't get the idea that the donut can't be precise just because it isn't designed as a precision reticle. I've seen some impressive groups shot with a donut.

Let's not forget that with the TA31 you get the BAC feature.  Worth the money in my book.  The TA11 and TA31 are the cat's meow in combat magnified optics.  Not to say that the TA01 is not a great scope, it is.  It really comes down to how you plan on using the rifle as to which would be best for you.  Do you "run and gun"? Go with the TA11 or TA31.  Do you benchrest, prone, or offhand shoot most of the time?  The TA01 would work just fine.  Either way, you'll have an awesome optic on your rifle.

DJ

Agreed 100%. You can certianly acheive excellent accuracy with the donut reticle. The donuts lack of a fine aiming point just makes the shooter have to concentrate more and put a little more effort into it.

A box stock TA01 is not as well rounded as a TA31, however with the addition of a Docter red dot sight I think the TA01NSN has some advantages.  BAC is a good idea but no matter how much you want it to be, a magnified optic is not the same as a 1x reflex sight.  

I'd also say that if you think the fiber optic on the TA31 looks fragile then you'll probably have the same concerns  with the Docter.