I've said it before in an ACOG thread, and I'll say it again.
I broke one (TA31F). Ocular lens chipped from the top of the housing down about a third of the way into the lens....on the inside of the optic.
Finally gave up after requesting manufacturer support and being denied and took the thing apart. Removed the chip and accompanying glass dust, wiped the lens down and put it all back together.
I take care of my gear, it was never dropped or abused, although I did buy it used in LNIB condition.
Stuff happens, even bomb proof falls apart occasionally.
Still.......I bought another. TA33 with the green horseshoe and I love it even more than the TA31F. Better eye relief, less magnification and the BAC works like a charm from 3 yards to 600. Yes, I've actually ran it to 600 too on a 66% IPSC steel target. Consistent hits were not a problem with my 16" middy.
Like others have said, I thought the glass was mediocre.
Would I buy another? Possibly.