I don't know if this has already been said, but look at the time of day when you are going too. Monday morning, Thurs. and Fri. afternoon, etc, are absolute no,no,nos for travel in my book because it is a zoo. I would guess that the upgrade opportunuties are limited during those times also.
Does anyone know the rule on the certs. given by customer relations for bad service? Can those be given away?
Phil