All these are moot points. I have travelled so often I could write a book on the Zen of Travel. About how foreigners hold up planeload of passengers simply because they can't read signs in Chinese, can't ask for directions in Chinese, had a fight with the cabby, went to the wrong end of the terminal and so on.

My advice is always this, be at the airport well ahead of time especially if it's your first time. Two hours is probably best, allowing you time to browse for books or souvenirs, visit the washroom, have a cup of coffee etc.

TS has 6 hours, enough to grab a cab to a nice restaurant downtown (the cab driver will most likely take a longer route to get there for the extra earnings), take a 2-hour meal and head back to the airport. Sorry to say he has no time to see the pandas.

PS: Here's a personal experience. I speak Chinese and it took me all of one hour to finally figure out where to buy tickets for the fast-trains from Hangzhou-Shanghai during my first time there. And this was all happening within the train station itself. I asked about a dozen locals and was pointed towards a dozen different directions.