I am thrilled with my Chef's Choice 120. I won't attempt to sharpen a knife without it. It makes them razor sharp and the edge lasts in my experience. I am seeing both a sharper blade and a longer lasting blade over other methods and I can do it. Thee only negative is the think cost me like $120. Also, the last 2 stages are used like 90% of the time. The model 320 might be 90% as good and it is only like $90.