For myself, I decided to pay the house off as early as possible and have had it paid off for awhile now. There are physiological benefits to being debt free, and while I have personally done pretty well with investments over the years, I've always been aware there are indeed risks. It's comfortable to us to know our future housing is covered other than taxes and sustainment sorts of expenses.
Personally, being somewhat conservative I can't imagine retiring while having debt. We debated retiring this year, but have decided to continue working one more year till I turn 58 so that we can build a little more diversity into our assets.