TA-31H user here. It was my first real glass on a real gun. I keep it on a ADM qr mount on my 16” carbine. Very usable and fast sight with both eyes open at close range (10-20 yards) And, the drop reticle is spot on for my set up with SS109 or M193 ammo out to 600 yards. Solid optic and it is not going anywhere for me. I considered selling and swapping to a LPVO a few years ago, but I’m of the mind set, if it ain’t broke, don’t break it.
If I ever build a new non SBR length rifle or carbine I will use a quality LPVO. But the 4x ACOG just works for me. I like it.