Satisfied !? Yes? or Nay?

I use these Sharpen bar for years and had no problems.
If some customers are dissatisfied with this Wetzstab I would imagine that the blades are incorrectly set for grinding.
A knife or scissors must be set at the proper angle to the bar. Unfortunately, sometimes not sufficient manuals are attached by the manufacturer, or not read by the customer because we think that can do that. And do not say that you that's not happening.
But now back to the Wetzstab "Gräwe professional diamond 25cm, this is also used professionally with me and I get all my knives sharp again without trouble.
If you then still have fix the knife at an angle of 15 to a maximum of 20 degrees, or exert pressure enough stamina, then you get all the knives sharp as a razor. Sharpen knives properly requires a lot of patience and there can in blunt knife before 30 minutes come together for sharpening.
So do not curse the same bar, but try again in peace.

In this sense I wish all users a good success.