Thanks for the feedback!
That was simply a Shapton Glass 16k edge. It was a 320, 500, 1k, 2k, 4k, 8k, 16k progression, only took about 10 minutes or so to sharpen. I believe it was sharpened around 15 degrees, maybe a little lower (I freehand everything), but there are a couple of reasons it feels so nice. The steel is very stiff, nearly eliminating edge rolling while sharpening (or greatly reducing it), the steel is fine grained (1st gen powder metal, but uses a different expensive manufacturing process), and the knife is nice and thin behind the edge with a great convex grind. Being thin behind the edge allows for faster sharpening (less steel to remove) and better performance, and it just feels sharper to the touch. They nailed the grind on that knife, it was a lot of fun. It will skate around on the stones a little bit due to the high hardness, but it does sharpen surprisingly easy somehow. Glad someone got it who will appreciate it!