I lived in Guangzhou and to me it is a great city with its mixture of old and new.
I have visited Beijing and it has the history and great places to vist (especially the Summer Palace) but it so sprawling it seems to have no heart ... and sure does not feel like it has a soul.
I had 5 days in Shanghai this year and had the overwhelming impression every day that it is a world class city in every way... architecture, planning, transport, etc.
The problem came when I when I wanted to show my son - he was visiting China for 2 weeks - the "real" China that I know. I was a visitor to Shanghai myself but in 3 days I had not seen anything that was very different from back home.
In the end we went to the "Old City". which turned out to be an up-market re-
creation for tourists.
Eventually I found a side alley where the locals were living in the 'old' way - old apartments, micro-industries, mahjong, people sitting on steps and chatting.
My son had been with a government funded promotion group, staying in 5 star hotels all the way, but felt that 2 hours in this place gave some window into the real China.