If it can be expensed and your employer doesn't care, the limo is nice. Driver will meet you inside, haul your luggage for you, and generally will speak some English.

But generally, I go with a taxi like Richard suggests. Just as good, and cheaper. Usually only limo if I'm dragging a tenderfoot higher-up with me.

If you are flying back out of PVG or SHA, then just get a taxi at your hotel.