Disengaging the lock is really hard to do if the knife is made right. Simply have the lock below your liners, and it shouldn't disengage. As for opening speed, I think back lock, compression, and liner are all around the same. The lock snaps in by itself. Closing speed, I don't care, but I'm fastest with a linerlock. I know it's dangerous in the sense your hands have to go in front of the blade, but I've been using liners exclusively until I got my Spyderco Endura. Flip the knife back, so it's spine down, with your index finger on the spine, and thumb and third on opposite sides of the liner. Now, use your thumb to push the lock, and then use your index to slightly push the knife up. Move your thumb back, and snap it closed with your index. Disengage and push slightly, move your thumb, and finish closing. It's almost one move for me now. If you're a lefty, or using your other hand, simply pull with your thumb instead. I can do it using either hand by itself. As for accidentally disengaging, it depends on the quality, doesn't it? Sure, the liner lock probably is the weakest, but it's still strong enough. By the time we reach the forces needed for a liner lock to disengage, you probably would have let go of the knife. So maybe we should start working out our wrists.
