When we bought in 2009, the rate was 4.85%. Later we got it down to 3.5%--a difference of over $400/mo. At this rate we'll have it paid off completely 14 years

When we bought in 2009, the rate was 4.85%. Later we got it down to 3.5%--a difference of over $400/mo. At this rate we'll have it paid off completely 14 years early.