Similarly, I used to always pay my credit cards as late as possible to take advantage of the use of other peoples money. Now I pay them well in advance of the due date because occassionally my payment would clear after the due date and the penalties would more than any miniscule interest I had earned on "their" money. With the advent of free automated bill payment I've now started to push my payments back towards the due date as I gain faith in the payments being made on time, every time and not being liable if there is a hiccup in the transfer.
All of that said, it is good of you to take time to educate others of the financial facts related to these early payments. Each person needs to make this decision for themselves because there are other factors besides money. Peace of mind is worth more to me than money and personally I'm not organized enough to make sure I don't get hit with penalties. For me, getting organized is like turning on the thumbscrews. I haven't truely balanced my checkbook or credit card bills in years. I