From Beijing Int/al airport to two different hotels

Hi. Three of us will be arriving in October. One will be staying at the China National Convention Center grand hotel and the other 2 will be staying at the Shichahai Shadow Art Boutique Hotel. So what we will do is go from the airport to the CNCC first to drop our colleague off and then go on to the SSAB. Should we take a taxi for these routes or use the metro? Also approximately how long will it take us to do this (afternoon)?
Thanks so much.