That requires the ability pay more than your payment. 15-year gets you a much lower interest rate. Due to rate drops, we were able to drop our payment by $200, lower the rate and knock 5 years off the remaining term.
In looking around with my son who is looking to buy a house I have not seen big differences in interest rates based on term. Could be different in your situation, obviously. And lots of other things have changed in the mortgage world fairly recently.
The beauty of paying even a little extra each month is how fast you start seeing a difference in the remaining balance.
