I've always had goodl uck with Expedia in the past, but we just returned from FL last night. After leaving Orlando we headed up to St. Augustine to see family. We were not pleased with the hotel we booked through Expedia and it took a lot of hassle and over an hour to cancel the room. At first they weren't even going to give me a refund (we found black mold in the bathroom, both boys have asthma...there is no way we were going to stay there). After a lot of hassle they finally refunded our money, but I'll never book through them again.
Just a side note, we have booked trips through Travelocity and have always had great customer service. We once checked into a hotel where the pool was closed (the gnome forgot to drop by and tell us). After a quick call to Travelocity they promptly refunded our money and apologized for the problem. No hassle at all.