Arrived at Madrid airport from Newark at the end of May. Flight was full and landed on-time. It took a little over an hour to clear immigration and receive our baggage because of the many international flights arriving at that time.
We had reserved the aerocity service via the internet and were pleased to find a brand new, well identified van waiting for us.
The driver was very courteous and quickly loaded our four heavy suitcases.
The trip to the Estacion Sur de Autobuses (around 11:15am) took about 25 minutes and cost only 2200 pesetas. (We had reserved using our Visa credit card, but paid the driver in cash)
Having previously experienced many times the unpleasent airport cab hassle, we strongly recommend the aerocity service!

[ 06-10-2001: Message edited by: MadridMan ]