No point, unless I really needed payment flexibility. Why sign up to pay more interest? 3.125% to 3.5% plus pay fees? No thanks. Or until the 30-year rates were well below the 15-year rates. Because the refi costs affect things substantially. As the other poster said, you'd need to be more specific than that.

If you need payment flexibility that badly, then maybe consider it. But that's really the only reason unless rates *REALLY* drop, in order to make up for the added fees and so on. (If 30-year rates approach 2.125% -- a point below yours -- then you may get to a point where it starts to make sense no matter what; you can always just pay more each month if you have the discipline to do it, and then come out ahead.)