All I can say is...
1) The St. Regis was one if the nicest hotels I've ever stayed in.
2) It sure was nice to come home to luxury after sweating it out in the Beijing August weather.
3) Pool is outstanding!
4) Make sure you get a breakfast inclusive rate plan.
5) The concierge was extremely attentive and provided excellent suggestions each night. (Peking Duck, China Club, etc.) and organized a chauffer-driven Audi A6 for our trip to the wall from a private company at rates far below the cost of a hotel car.
No idea about the Sheraton.