Pay it off. Its odd how over time peoples perception of home ownership has changed. But, so has mortgage rates. Growing up, people didn't use terms like equity. They didn't borrow EQUITY to remodel their house. They paid it off and got out of debt. I can see the investment side of it. But, like others have said, peace of mind is worth a lot. If you own your house out right (other than taxes), nobody can take it. On the investment side, I would worry about waking up one day, 401k is near zero, lay offed, and wondering how I'm going to pay the mortgage?