Many of the TA01NSN owners have added either Docter or Optima 2000 red dots on it to address the TA01 fine cross hair Christmas tree reticle's shortcoming in CQB. Folks have made their own mounts, the easiest way is to get it from
specwargear.com/ (click on Sale on the left pane, then click on SpecWarGear Sale Board), they make the mount for Docter and Optima.
I have also followed other means to compliment the TA01's CQB capabilities, such as putting an Aimpoint directly in front of the ACOG. This would also be unnecessary if you have an ACOG that can do it natively.
If you don't already have a TA01NSN, my advice is to get an ACOG with BAC, I suggest either the TA11 or TA31.
TA11: 3.5x, longer and heavier, but great eye relief. About $1000.
TA31: 4x, same eye relief and size as the TA01. About $850 new.
TA01NSN+Docter: higher profile, cheekweld non-existent while using the red dot, added expense. $750 for the ACOG, $250 for the Docter, $60 for the ACOG adapter mount.
TA01NSN+Aimpoint: expensive, reduces the ACOG's light transmission (from the blue tint from the Aimpoint), makes the weapon slightly heavier and bulky. $750 for the ACOG, $300 for the Aimpoint, $150 for a cantilever Aimpoint mount.
These prices vary a great deal, some models come with the Trijicon's own flat top adapter (TA51) some just the M16 handle mount.
Note that BAC requires some training to use effectively, the TA01+Docter combo is easy to use.
I like my TA01NSN, but I'd stopped trying to "fix" it by adding more optics to it, instead I got a TA31 and TA11 for all purpose use, and just mount the TA01NSN when I feel like using the cross hair reticle.
Hopefully other TA01NSN+Optima/Docter owners will chime in
Now here come some obligatory pics
Normal TA01NSN reticle:
TA01NSN with Aimpoint directly in front, notice the blue tint: