And where will they trade their account from? A cardboard box under the bridge?

And where will they trade their account from? A cardboard box under the bridge?
Well, of course there is rent.
The Penfed 5/5 arm is da troof

The average person does not have the discipline to pay more than the minimum each month. So your estimated savings of only a few hundred each year is based on an assumption that the average borrower is as astute as us CFA-types. The true comparison is the $39.7k vs. $95k.
Do you actually write out a check for your mortgage every month? People can just setup an automatic payment at the higher amount.