The best part was the contrast between historical China, the Great Wall, the Forbidden City, Summer Palace not to mention the Yangtze Gorges, and with modern China. Vast motorways criss-cross the country with splendid overpasses and underpasses. A Maglev (magnetic levitation) train can whisk you at 300 mph out of Shanghai to its ultra-modern Pudong Arport; a bullet train carries you at 125mph to the Yangtze at Chongquin; overnight trains transport you from city to city; when they meet a mountain the railway line just goes through it with many kilometers long tunnels.
Spellbinding architecture in the cities include a 101 story high, 3rd highest in the world, Trade Centre at Shanghai; and 4th & 5th tallest at Hong Kong (our own add on to the trip), not to mention the forests of skyscrapers in these and other cities. The telephones were excellent, only the internet from and to overseas sites is a little slow, the hotels excellent.
By contrast much of the older building has to be seen to be believed.