Thank you for the replies,

I think my biggest concern is facing a situation where no seats are available.

[QUOTE=HongKonger;18296224]When you check in online, you will be able to purchase a preferred seat if you wish. The charge will be per segment, I'm not sure how much or if it varies from flight to flight. If you don't purchase a preferred seat and no others are available ahead of time you will be assigned a seat, possibly as late as at the gate, and it may or may not be one of the preferred seats (as others with existing seat assignments may have bought into them, freeing up a non-preferred seat).

If you don't want to pay for a preferred seat and you don't want to wait for a seat assignment, check DL.com early and often to see if something you do want opens up. Or set up seat alerts on EF if you have it.[/Q]