We used Magical Express for the first time last week. It went OK, but there were a couple of annoying things about it.
#1--Because the luggage tags never arrived (even after we got home), we claimed our own bags and carried them to the bus. Amazingly, we saw that most people were doing likewise. This meant that the buses took much longer to load/unload since the luggage had to be handled. If they ever get the system working so that people do not have luggage, things will move much more quickly. From the time we got to the ME counter until we got to our hotel was approximately 2 hours.
#2--Our flight was at 7:50 p.m. ME gave us a pickup time of 4:00, which meant we had to be at the bus stop by 3:45. We got through security by 5:30 and had over 2 hours to kill sitting in the terminal. Not cool.
We just kept telling ourselves that it was a free service. If I had paid for it, I wouldn't have been very happy.