Let's use Mark's as example - The rate is so low, you can use the money to invest something very conservative and make 3% plus; After paying 1.05% Mark can make net 2% of 5.95 mil; that is almost $120,000 per year "free money". Any time when rate is up till it is higher that his investment return, he can simply pull the money out from investment and payoff the mortgage.
You don't need to be as rich as Mark to do the same thing. There is ARM for primary property at 1.875%; if you can always payoff your loan,you can do it to make extra vacation money.
This also can answer a frequent asked question - Should I pay off mortgage or should I use $$ to invest? If your investment return rate is higher than your borrowing rate (the cost of capital), you should invest; if you put $$ in checking account, even the monrtgage rate is 1%, it is better topay it off.
I did go to watch movie yesterday as usual. The movie is a good one but I felt a little nervous - paid several looks around people sitting around and peopel walking in through the entrances. :>) Have a safe weekend!