I’ve ran the numbers to measure extraction with a variety of distribution methods and I discovered that OCD alone (this mirrors a lot of the consensus here) does not properly distribute coffee. You need to manually “pre-distribute” before using the OCD to achieve consistent results. My experiments (which I will publish internally then probably on my website), showed wild deviations in extractions if you only use the OCD. I’m recommending for busier cafes the OCD is a cool tool but it’s an extra step that isn’t necessary for tasty shots.