Thank you, all! (And, another thanks to Jiejie )

Just to re-cap: Is the consensus that the public transit option generally takes the same amount of time for the time of day and day of week as a taxi, but is more reliable? I've basically budgeted 90 minutes each way for public transit -- which eats up 3 of our precious 9 hours. If a taxi would give us another hour downtown and be as reliable to get us to/from PEK, then we'd opt for that (despite the additional cost).