What are your dealbreakers? Seat comfort, food, service, nonstop flight?

For me, I'd choose KE because even though it's J instead of F, the service is more likely to be better and it's nonstop from JFK. Plus, if you're on a KE A380, there's a bar sponsored by Absolut Vodka in the back of the upper deck for F and J passengers. There's also a small duty-free shop at the back of the lower deck. However, J food was mediocre and I was disappointed in their drink menu selections. Plus, if you're on a full flight, their J configuration is 2-2-2, so you'd have to hop over someone sleeping if you're at a window seat.