My Spyderco Stretch is in ZDP 189. While fairly hard, it is not in the same class as the Spydercos made from S110V or K390. Sharpening was consistent and fairly fast with the Aluminum Oxide Edge Pro stones. I used the Stretch in the test at the end of the thread on the Improved method of using the Edge Pro. It only took one very well placed stroke to bring it back to hair shaving sharp after several weeks of use. This steel is growing on my. It has been easy to sharpen, takes and holds a edge way better than S30V, S35V and similar steels, and clean looking too.
see the pictures here. improved-process-for-consistant-edge-pro-angle-set-t8437.html