I've had mine a year and I've never calibrated it. I know there is a way to do it... AM mentioned it. I usually choke my home roast one step down off the right, with the left lever fully up. A roast I bought from a local roaster a few weeks ago (peru) needed a bit finer, but nothing the Vario couldn't handle. So what are the benefits with calibrating it AM? I've still more than happy with mine. I have noticed it makes a noise as the grinder is slowing to a stop after grinding. I can't remember it it was there from new, but it's still running and the grind is still the same. I've only cleaned it once, and it was very clean inside, unlike my previous Rocky & K6.