mortgage buyout
There really isn't a simple answer here...
If you payoff the entire mortgage in 38 months, you will save $X in interest. If you don't pay it off, you continue to save $Y in tax deductions for the mortgage interest paid. The problem of $X - $Y is not as simple as it seems though... You also have to think about if you took the money to pay off your mortgage and invested it sooner, would you get a greater return on your investment rather than buying out the mortgage on your house. Especially when the market is in the state that it is in today (buyer's market).
I pay off 18 mortgage payments in 12 months, thereby reducing the overall interest of the mortgage over the length of the mortgage and increasing my principle. This allows me to have some additional $$ for investments, entertainment (fun), and emergencies without much sacrifice. Obviously I am taking a bigger hit on the mortgage interest than if I paid more, but for me, owning a house means I make payments. If I sell the house in a couple of years, it adds up to more $$ in my pocket because of the increased principle I paid off.
Short answer: It is a personal decision.