I LOVE the Park Hyatt SF. I even use my FFN to stay there during the week if I find I am nearing the end of the redemption period since my company won't pay the $250+ they charge on weeknights. I am a Diamond and have always been upgraded, at least to a Park Room, someimes to a suite with a whirlpool tub and window in the shower. All rooms have a goosedown comforter and Frette sheets and a Nakamichi CD player. the little bar tucked away on the 3rd floor is superb. (I found out that everyone in my department heads over there for drinks after work, even when I am not in town). They have the best martinis in town. Breakfast at the Park Grill is great, ask for the lemon blueberry pancakes even thought they are not 'officially' on the menu. I actually prefer the Park on weekends since there aren't all the fanny-pack clad, t-shirt wearing, camera clicking tourists you find at the Grand. The Wharf Hyatt is awful on all counts. You either have a view of another hotel, a warehouse, or a pool full of noisy children. The rooms are small and there isn't a decent restaurant within walking distance. On the other hand from the Park you can walk to many wonderful restaurants: Aqua, Boulevard, One Market, Jack's, Harbor Village, Shanghai 1930, Zare, the list goes on.