The discount for preferred is up to 30% off at the Premier (Portofino, Hard Rock, and Royal Pacific) and Preferred (Sapphire Falls) hotels, and up to 25% off at the Prime Value (Cabana Bay and Aventura) and Value (Dockside and Surfside) hotels. They are subject to availability, they only have a certain amount of discounted rooms. And the rate is available about 90 days in advance. If you're curious about rates, you can play around with some dates without an AP
on the website