Another option is to use Yamato Takubin to have one's bags sent to the airport the day before departure, and then take the train with only small cary on luggage.

That is not always practical when staying at an hotel though, so I agree that the bus is very convenient, even if slightly slower than the train.

A good pount about N'ex is that it has green car service, which is more spacious and can be less crowded.