Originally Posted by
hjohnson
In reality this should be a moot point on many routes. If you decline your upgrade, there will often be someone else waiting for an upgrade. In effect, you're just trading seats.
But it's not a moot point. As has been pointed out in several other threads, if you actually get the upgrade and then try to downgrade again, you will have to pay a fare difference if there is nothing left in the fare bucket you originally bought from. That difference can be pretty harsh if you are forced to go from W to Y or B.