Personally, I'm anti ride-sharing apps upon arrival (only) from airports in China. There are surely some exceptions, but my position is well supported at both Shanghai airports.
Sure, you will save around 20% v taxi, and your odds of being ripped off (e.g fast meters or longer than necessary routes) are very low, but the pick up process/location is sufficiently annoying to nullify these upsides (IMO).
Others disagree with me, and have compelling arguments, especially for far away destinations (e.g 20% off of 500 justifies the hassel).
I'm even more opposed to anything that entails using Maglev.