The new NKG airport is really easy to get into China - not so much international flights, so when flying in C (or first rows Y) you're almost guaranteed no queue. Baggage is out quick as well, I've made it from wheels down onto the highway in less than 20min quite consistently. Without priority tags (seems to be working fine, both for *A as well as ST) I guess you might have to add a few minutes.

In short: If you are going for anywhere in between Shanghai and Nanjing, I'd definitely prefer going via NKG over PVG.

SHA is a different kind, as it's easy to use with the trains, but NKG isn't too bad either. Take S-Bahn from it directly to Nanjing South station, where most of the High-Speed Trains are leaving from (Nanjing Station in the North still has some, but not that many anymore)

Considering long haul you can't really get into SHA, NKG wins hands down over PVG.

Unfortunately only Lufthansa is flying there from Europe directly, and only 3x weekly, but whenever it fits my schedule, I'll use them. It's SOOO much less hassle.

If your final destination is NKG, and you're landing in PVG, there is 1x daily MU flight - obviously a joke as a city-connection, it works well when you're in PVG anyway and needing to go somewhere in NKG that isn't really in the North of the city.