I've got the two-piece opti-locks on one of my rifles, however have made them permanently one-piece now... I had problems with the screw that threads up into the ring from the bottom of the base (on my front ring) Recoil over-time (from my firebird 7mm) stripped that screw & it would loosen and lose zero.
Since then, I did put one of Richards rails onto the firebird and use a completely different set-up on-it.. BUT
Regarding the (now permanent) opti-lock set... I basically took that set that had the screwed up threads due to recoil and torqued them together using JB-weld on the threads themselves as a locker, as well as inside/inbetween the recess the ring mates up with the base... I did the front & back ring/base both
I figured they were damaged anyway, and I have another rifle I can "try" this "fix" on, so I'm doing so.. and so far so good. They're solid. All that said though, I ONLY did it to make use of what I already had.. So save yourself the hassle and get one-piece opti-locks right off the get-go (or) splurge and go with one of Richards rails-- he keeps a few in-stock always, and is an awesome guy to deal with.
Biggest plus with a rail, you're options for rings & scope-tube sizes is unlimited*