I/O are great for the people who can see. Unfortunatly they got a bad rap from the blind who never understood what happened at the end of a 3/5 or 10 year term. Knowing your income, what happens at year 11 and being able to pay off your now 20 eyar fixed rate loan is what is needed. If in 10 eyars you can re-fi down the great but if in 2017 the interest rates are at 10% then really your 20 year at 6.25 would probably workout the same per month than a 30 eyar at 10% rate.
Be smart with your extra money, save, invest and don’t wash it away.