I think that Gerber makes two: the AR3 and the AR3.5. I started my love of knives with the AR3, TYVM.
I still carry and use it at work, on industrial tape-machines on a shipping line. Serves me faithfully, and is sturdy on lock-up and convenient one-handed in-&-out of loose pocket.
I think (well, I'm guessing) that you are confusing liner-locks with frame-locks. Many people confuse the terms.
If you are confusing the two, I agree; My two edc's are a Cuda EDC (frame-lock) and a Gerber Gator (lock-back) {modified with a Bandit* after-factory thumbstud}. The liner lock on the AR3 is fine for factory work though; it's never failed me in prying/ripping/poking.
Just my .02