I prefer the betterbidding.com site - you can post there and ask questions there, and they will direct you - they have a list for priceline hotels, and hotwire hotels.
they also are good at telling you when it is better to use hotwire, and when you can use priceline!
ITA that hotels do know if you are a PL customer - their hotels put their inventory into PL - and I also agree that you can check in, like at Disney, and your room may or may not be ready! I've checked in at 9AM in a Chicago hotel - usually my room is ready, if not they will store my luggage for me while I hit the town!
oh and I think they reccommend looking on hotels.com to find the inventory for the city you are looking at!