I've used Priceline for most of my hotel room bookings with no problems. But I've read horrible stories at this site and biddingfortravel where the hotel was full/over-booked and they refused to honor the priceline reservation. If you're lucky, they will get you another hotel room & paid for it. If not, you will be stranded and have to pay more expesive rack fare on your own.
No cancel & no refund is ok with me, but it should work both ways.