The Trijicon ACOG QD mount is actually made by BoBro, but that is a big plus in my opinion. I've been using BoBro mounts on my aimpoints for some time and when I went looking for a QD mount for my TA31F I was happy to find the ACOG mount was a BoBro-manufactured product.
As with their aimpoint mounts they use the same type of QD mechanism and it retuns to zero each time I have dismounted it (tested it several times at the range to test zero). It hold the rail very firmly with no slippage or movement, period. If you are looking to replace your TA51 mount with a QD mount that returns to zero every time, I'd highly recommend this mount.
Pros: Returns to zero, firm mounting
Cons: None (it's not free?)
This review was written in the old system and had content requirements that are different than reviews written today.