My good old 0560. First "good" knife I ever got.
This thing has gone through it all. I have used it to cut up tons of thick cardboard, chopped down small trees, pryed various containers open, lent it to people who destroyed the edge cutting fiberglass and steel wires, slashed open more aluminum cans than I can count, used it as a throwing knife, and worst of all used it to baton firewood on a camping trip (as in splitting wood thicker than the span of the blade).
Between sending it back to ZT for Elmax-related edge retention issues (all they did was grind the edge back a ton at about a 60 degree angle) and all the other times I re-profiled it after the edge got destroyed it's no slicer. That edge that looks like it is really lean is actually 40 degrees inclusive and there are still chips that haven't been sharpened out. There is also a crack going from the thumb stud to the spine of the blade that appeared recently.
There is horrible vertical play and lock-rock from batoning and although it is still really smooth you can feel the dents in the bearing track left from prying as the bearings roll over them.
The g10 around the pivot is all scratched up and full of super glue from where I stripped the pivot screw and had to fix it to the scale and rotate it 180 degrees, break the glue, and fix it again repeatedly until I got it out and could put a new screw in.
The steel liner under the G10 is covered in rust spots, the clip was DIY blackened with a blowtorch and has worn to what it looks like now, and there are still some spots on the titanium from where the knife stabbed half-way through my palm (my fault) and got soaked in my blood.
Despite all of this the lock never slips, there is no sideways play, it drops freely even with lockbar tension, the detent is still the same depth into the detent hole that it was when I first got it, and overall the knife is still mechanically sound and I see no reason to stop using (possibly abusing) it.