The 110 folder has had people talking about lock rock as long as there have been places like Blade Forums to talk about knives on. They are known as quality knives but the traditional backlock designs will all have it to one extent or another. It's the design itself and not a defect. The Schrade LB5, 6 and 7 ( 50, 60 and 70) too. The old Camillus designs, the "Remington" models ( made for Remington brand by various companies ) also. All of them will show some movement if you look hard for it. Pinned or screwed matters not.My Buck110 a full lock back does not exhibit this and I own more than one of these none of them rock. They are also pinned construction.
I have seen it in the Cold steel designs both old and newer triad designs. Some have less and some more. What I'm referring to is a tiny flex and not real up or down or side to side movement.
That it is pretty subjective among st us knife users seems obvious. . Some will hardly notice what others will lose confidence in. That is the point. If you have lost confidence in a knife then you should probably get rid of it, send it back, in for W&R , whatever is appropriate. That little flex that I can find if I'm looking for that doesn't show up in use does not disqualify it for my uses .