How long it takes from Beijing airport T3 to Beijing West Train Station by airport bus 7?

Hi there,

I am wondering how long the airport bus #7 from Beijing airport T3 to the Beijing West Train station may take? The flight arrives around 3pm on Wed. Also the stop at the west train station is still 1KM south to the station itself. What is the best mean to get to the train station? Taxi?

Thanks for any inputs,