I just took the high speed rail around the area, from Shanghai to Nanjing and back then from Tainjin and Beijing.
The only drawbacks of high speed is that there might be some really obnoxious people, I had a guy next to me talking very loudly on his phone. And the taxi line in Shanghai was 2 - 3 hours long so we had to negotiate with some dude to get a car and got ripped off (250 rmb to Doubletree Pudong)