The main purpose caught my interest. Trying to gather three knives of a same steel/maker caught my interest.
It went downhill when I got that the proposed deburring method(s) was not the stones themselves but leather or cork - the unclarity of why and where to use any of the two further throwing this downhill.
Then seeing this guy pushing equal force = like a madman into a NP400, Debado 1K and Morihei 4K... aaaaah. I stopped there. I could be wrong but will take a guess that he'll see no difference.