I have a 350BT plainedge version. It locks solid and isn't hard to unlock if you push with edge of thumbnail.
One odd thing. I was cutting some thin cardboard the other day and I noticed the BT2 coating kind of wearing off in some spots. It's weird because the BT2 coating on this knife doesn't seem as tough as that on my AFCK.
But the 350 holds an edge, is very sharp, and so flat it's easy to forget it's there. A great knife for the $$!
Jim