I recently booked two nights at the Portofino Bay Hotel thru Hotwire. I will be arriving in a couple weeks and my credit card has been charged already. As long as you have a clue as to what you're getting, Hotwire seems to be the way to go.
A few years ago I used hotwire to book a car rental in CA. The price we got could not be touched by anyone else. And we ended up with Budget and everything went smooth.