My A-F folder's lock is very reliable. I can rely on it to fail every time with a moderate whack or pressure on the top edge or spine. Mine has a sharpened top edge so this lock problem is clearly a fundamental problem.
How do you test it? Carefully. The knife is big enough to test while holding with your fingers clear of the blade path. If you're not comfortaable with that or haven't done it before, have someone more experienced show you how. It really isn't very difficult.
I'm also not impressed with the one sided liner. I would have liked a clip, which mine doesn't have. This is a relatively big, heavy folder, which is good. I like the design, which is why I bought the knife, and because I've come to associate Gerber with toughness and quality. I've had all kinds of Gerbers over the years. My first serious knife was an old Gerber Magnum Hunter, which is completely indestructible, and I have innumerable Gators and other lockbacks. This is the first piece of garbage I've ever had from Gerber: and any folder, especially a double edge fighter, that has an unreliable lock is worse than garbage: it's a hazard. Shame on them. Somebody, maybe a youngster who doesn't know better, maybe someone who actually needs the knife in an emergency and didn't adequately test it, is going to lose some fingers or suffer permanent damage.
I can't remember who, but someone is making custom or semi custom versions of these knives. If you like the design, try that. Don't risk buying a production version. Even if yours won't be failure prone when you buy it, I wouldn't trust it to last very long, as I would trust a BM, or a REKAT, to mention only two. Even then, you should maintain and test any liner lock periodically, no matter who made it.