I like the flexibility of the I/O. I’m an investor in different enterprises (some RE developments, some startups, etc – my wife says, “what exactly do you do?”) so when a good opportunity arises I need to be able to fund it quickly. Right now I have a good deal of cash so I’m applying extra cash to the principal which is probably dead money for the next few years, but it pays down the loan balance a bit. I’ll move in about 10 years when the kids get out of college. I guess it would be good to have the house paid off, but I think I can put the money into assets that should appreciate 3-5x traditional housing returns. If this decline is like past ones we’re about 2 years into a 6-8 year decline. After that I think prices will begin another climb where prices double from the bottom in about 5 years. If I play my cards right I’d like to buy my retirement house in about 3-4 years at the bottom and then unload my current home as prices start going up again.