I bought my brother one of those for Christmas, he’s been a knife sharpening guru for decades now. He loves the thing, I knew he would, his knives were all between 100 & 300 when I gave it to him, his 2 main pocket knives were both below 200. Now he’s playing with different stones and such competing with himself.
If something shaves, it’s good enough for me. I use the little work sharp belt sander, which my brother calls cheating, but it sure is easy.