At one time I was very skeptical of the Sharpmaker...it just looked a little too simple, too gadget-y, or something to me. I also just didn't see the need for one, there was no way it could compete with my collection of waterstones, oilstones, etc, etc.
Well, then I got to try one, and the first knife I sharpened with a Sharpmaker happened to be a Henckels "Classic" Santoku.
When I started the knife wasn't visibly damaged, but was not sharp enough to cut cleanly through phonebook paper.
I followed the included instruction booklet step by step, EXCEPT rather than the 40 strokes (20 left, 20 right), I did maybe 10 left and 10 right (I wasn't counting), moved to the white rods, another 10 or so left and right strokes (I was in a rush to prove to myself the Sharpmaker didn't work!), and after a quick strop on my pant leg I'll be damned that knife glided through the phonebook paper!!
I noticed it had a little spot where it hung up at the tip, a few more strokes on the white rods, and wow! Right through the paper.
To be honest it wasn't perfect, it wasn't a mirror finish, it wasn't the sharpest knife I'be ever touched, BUT the Sharpmaker WILL sharpen a Henckels knife.
So without any judgment intended, you must be doing something wrong.
Start from scratch, take your time, read the instructions, and check your work, meaning check the sharpness of your blade before you start (cutting phonebook or other paper), and after 10-20 strokes on the brown rods, then again before switching to white rods, then again after 10-20 strokes and so on.
You SHOULD see improvement in the sharpness of the blade.
It WORKS.
I still prefer my waterstones, but I do use the Sharpmaker, and it WILL sharpen your knife.