We have a Heloc that is autodrafting each month. Unfortunately, if we pay an extra payment, the autodraft will be for that amount less than normal at the beginning of the next month. We have had to change to paying the full payment plus whatever extra we want to pay on our own through our online banking. Not a big deal, but something to watch for.
Our mortgage lender (MetLife) gives you the option to pay biweekly and pay it off early. But, they charge a set up fee of about $300 and a an extra fee out of each payment. Not worth it. Better to pay extra on your own.