Other hotel options (with good pools):

Puli Hotel: centrally located downtown next to small park, nice outdoor seating, good rooms & amenities, infinity pool (indoor).

Peninsula: located on the Bund, best spa in town, nice pool with outdoor terrace.

Hyatt on the Bund: quality pool and spa, decent location (north-Bund), nice bar at top floor.

Intercontinental Expo: i know its out of the way in Pudong, but i have a soft spot for this hotel. A great spa and swimming pool (very private, usually no-one there), outdoor seating area, and great river views from the gym.

And i'd choose the Shanghai Hilton over Hongqiao Hilton anyday, unless i had business in that part of town.