When I refi’d in December, (rates have changed, concepts might not have) I had 20% + equity either way. I could get a conventional at 3. 8% and avoid pmi or go FHA at 2. 99% with . 8% pmi for 11 years then it drops off and I am effectively 2. 99% for the rest of the loan. Seemed easy enough math to me to take the pmi until it drops off. At either of those rates, I feel zero incentive to throw an extra dime at the mortgage. I would rather invest it, that is not a hard benchmark to beat over the life of the loan. The part that I relate to you would be the benchmark, how would you deploy the extra cash vs the cost of mortgage + pmi which would be for the life of your loan.