So yeah, the JJstaff S1 capo: as advertised, it goes on easily and can slide between frets quick and easy. It's attractive. It's well made. It works well as a capo. It's just not gonna be worth $75 to the vast majority of musicians I know. The Kyser capo works well and I can buy 5 for the same price.
Love my new Jstaff capo! If I see a guitarist, I corner them and Airdrop a link to them. Well done!
This sliding capo is ingenious. I have only had it a month so its durability will have to wait to be determined. But it works great and much easier to se and attractive and less obtrusive on the guitar than other sliders have had.