I've booked a couple of U.S/China trips recently. Both times, I compared the prices on both the Delta and Korean Air websites. Last time, Delta was significantly ($600+ for economy) cheaper for exactly the same flights; this time, Korean is cheaper by roughly the same amount. Any idea why? Any downsides to booking through the Korean site? One upside is that I can choose my seats -- and pay a bit extra for the extra-legroom seats. A huge pet peeve of mine is that when I book Korean metal through Delta, Korean puts me in the back of the bus, middle seat; there's no way to change seats, and you can only buy the extra legroom the day of travel (assuming it's available).