I've never used Hotwire before and would like some opinions about the quality of service. Has anyone had a particularly bad experience? I understand how they work--that you don't know the hotel until after you book, its nonrefundalbe, can't be changed, etc. However, has anyone had a bad experience, such as arriving and their reservations aren't in the hotel's system, or being double billed on their credit card? What about the quality of the rooms? Do some of you feel the poorer quality rooms are given to Hotwire users? How are you treated by the hotel? What if there's a problem--can you talk to the hotel or must you call Hotwire? What's their customer service like? Opinions, please!