We bought a 3-day metro pass from the machine in the international arrivals area for $18 each. We were able to use it for the 747 bus and 3 days of metro usage. We didn't use the metro as much as I originally thought, since so many of the places we visited were in easy walking distance.

I thought the 747 bus was fine and it had a stop one block from our hotel. We thought about getting a taxi from the airport for the 3 of us, but then figured we would get 3 days of metro usage as a bonus for about the same cost.