Which Grinding Disc is Actually the Best?

See the results for every disc real time as I post them at the Fireball Forum here: https://fireball.discourse.group/t/grinding-disc-tests-megathread/3061 I want to test flap discs to find the best one, but in order to do that I need to design an experiment, build a machine, and collect data. So join me as I embark on this journey of shop science! I have questions that need to be answered, questions like: Which flap disc should I buy? Which flap disc is the best? Is there such thing as the best flap disc? Which flap disc performs the best? Which flap disc is worth it? Which flap discs should I avoid? fireballtool.com