If your mortgage is way over what you would be paying for rent,and I suspect it is,then yes it is a business decision. If you don’t think you will be out from under water in 7 years,then go for it. Let me caution you that we could very well have another bubble and you may ruin your credit for no reason,hell the market went up 3% yesterday,anything could happen. I’m also assuming you are not married,if you know you won’t be able to afford it when the loan resets, then you are a renter.