Hello. Hope that I don't get thrown out before I start, but espresso isn't on the cards in the near future. I'm just looking to improve the flavour of our filter and French press coffee. Would a used commercial work for this or is it just overkill and daft? Strangely I just like the idea of a big solid chunk of metal in the kitchen. Usually brew 3 mugs at a time and wasn't think of anything manual. Is a worn out commercial as bad for coarser grinds as it is for finer grinds. Thanks for any comments.