To be honest from digging up threads on Gengetsu (before the restock), I'd gotten the impression that it was going to be a bit heftier and thicker than mine is. Maybe my understanding of middleweight is heavy compared to others'. It's perplexing me because it seems to have similar spine specs and look & feel of the grind compared to a couple of others I have, yet it seems to just slip through foods a little bit more effortlessly. And the tip is just silly.
I am feeling the same. It is very nimble and fairly light but still stiff. It is similar to an Itinomonn in hand but performs a might bit better. Better flat area and the tip is so nice and thin. I haven't touch it up yet. I used it a full day at work and I think it could handle a few more days before needing a trip on a fine stone. The SSS core took a matte grey with a touch of blue patina kind of like Itinomonn SSS.
Still need to try it out on a number of other items but all in all it is a nice knife.