I’m actually doing it. The biggest expense (one you haven’t mentioned) is the hit to the FICO score. Carrying high balances will certainly ding it. If your score is high enough that you don’t care (800 or 770 gets you the same mortgage) and/or you’re not planning to apply for a mortgage anytime soon, then that doesn’t matter. The rest (time, expenditures) is very, very low, close to zero I’d say. You can open an account online in 5 minutes and set it up for automatic payment. Of course, you have to watch the fine print carefully before you apply, because there are all sorts of tricks, like 0% is only valid on transfers, not on purchases, and the other way around.
The best deals I’ve seen are from Capital One; they will basically cut you a $30K check, and charge no interest for about 15 months.
