I’ve used it before. It’s pretty nice. But I find the wicked edge system much easier. I will say that this possibly has an advantage on larger blades however.
You will see lots of people say that this Russian one is bad because the angle at the tip is different than the angle at the base of the blade because of geometry. Not true, it maintains the same bevel angle the whole way. I won’t lie it’s a really good system. Very smooth. I just really like the wicked edge mostly because most my blades are in the 6” or less category except for my kitchen knives.