I have paid and will continue paying for upgrades depending upon circumstances. For example, when staying at the Hilton Hawaiian Village for Christmas I will upgrade because I know that no complimentary upgrade would be offered as the hotel will be sold out. I also paid for an upgrade once as the agent refused to upgrade me any further than a King room (from the original Queen) stating that it was their policy and I did not want to argue. Paid a couple of times from a suite to a higher suite as I knew that that would not happen complimentary. There is nothing wrong with paying for an upgrade. I think when a particular type of the room really matters to me I would rather pay than be disappointed.