I've had two, both CC and new lock up, both second hand. First one solid then sold it, second one also solid at least initially, then eventually i got some lock rock. I did not use it hard at all, the lock rock was not so bad in my opinion, initially a little disappointing, but then i realized in actual use i could not even notice the movement. The only time i noticed was if i grabbed the blade and wiggled it up and down or shook it up and down vigorously.
I got to thinking that it probably developed lock rock from me testing for it a few times lol, honestly. Also i think part of the reason they may be prone to lock rock is because the contact point on the lock bar is only a small part, and so if you constantly force it up and down (testing if it for lock rock) then i think that small point of contact gets worn down a little bit and creates a small bit of space causing the lock rock. That sort of rocking motion doesn't happen in normal cutting since when you cut the blade just gets pushed up not up and down. So maybe it's user tendency to wiggle the blade up and down that is causing the play.
I have to say it did not bother me as much all things considered, it was still a secure and solid lock to me. I am wanting to get another SNG actually right now, i wanna try a lego, never had one a those before.
There is something really cool about striders, i love CRK, i can always expect everything to be perfect, but a CRK still doesn't satisfy that craving for a strider, strider has cool factor and is really comfortable in use and funner to open and close. CRK is beautiful but a little boring sometimes, just a little in comparison to some other options, but i still adore CRK and a week without one and i'm gushing about em next time i have one in my hand.