Update: we had a fantastic time in Shanghai - thank you for your suggestions. The weather was sunny and mild in the daytime and cold at night - so perfect for exploring.
We stayed in the Radisson Blu hotel - opposite People's Park, and it was a great location and very nice hotel, also reasonably priced for the quality. It has a pool, with spa pools, so was perfect for relieving jet lag and travel aches.
We had many issues with Alipay - sometimes it worked, other times it wouldn't. We got by though. It wouldn't let us buy any beer, so there must have been some restriction on our settings, which I couldn't identify. Staff in the metro were very helpful, patient and kind.
I also couldn't get my VPN to work so we used old fashioned maps, or just followed our nose.
We arrived using the Maglev, saw the Bund lightshow, Jin'gan temple, walked the length of Nanjing road, wandered around back streets and saw lots of tradition in amongst the high tech buildings; went in one department store, but that was enough as it's very sensory overload in them with all the people. Thought it was very Chinese that the staff had number badges, rather than names! Some of the underground clothing shops were tempting but I was so tired that I couldn't be bothered trying anything on. Also, shop staff are all over you if you even touch anything, giving the hard sell.
I was surprised at how elegant the city felt - more like Manhattan in parts with trees and wide avenues. I really enjoyed it and would like to return when we can spend more time.