Some of the best sight seeing are actually around Shanghai. Suzhou about 80km to the north and Hangchow about 200km to the south. Both are acient cities rich in history and culture.
Shanghai itself has gotten more congested and polluted. The JC. Mandarin is one of three five star hotels. It is run by a singapore chain and located in the center of the city.
Have a great time in China and email me if you have further questions.