Hilton HHonors - Reward Question- stay 3 get 4th free

Mentions on the site to check when you make your reservation whether your rate qualifies. My question is whether anyone knows if this reward is pretty restrictive to paying basically rack or whether it's doable with AAA rates for instance. Thanks!

Rack, Standard or Business rates. Generally you will not find much use for this unless the property is pretty full (and then us still may not be able to use it because of capacity controls) 4 days at a AAA or AARP rate will often be cheaper than 3 days and one free.
Mike

Thanks for the 411. Seems that outside of VIP awards, which are great, HH is not so hot on rewards.