I put a family member at the Miami Beach Four Points through priceline and he also had a very unpleasant stay (problems with room, broken elevators, etc). I gave him the Starwood Customer Relations phone number (see omni thread) and they gave him points worth two free nights. He then went back for three nights, and they comped his whole stay. This time he found the property acceptable.
I generally agree with the assessment of Four Points. It's very much a crapshoot -- and the odds aren't on your side. They should definitely toss out the bottom half of the group and start over. It wouldn't be hard to figure out which hotels to let go.