I used the Express line on both ways between the Suvarnabhumi Airport and the Makkasan Airport Rail Link station because my hotel was near Asok BTS station.
Express trains from the airport depart every 25 mins past the hour while trains from Makkasan station depart on every start of the hour. The whole trip takes around 19 minutes.
The trains were puctual and fast. Staff were helpful to answer questions and give directions. I am surprised that not many people are using it yet.
The only thing is that there is a short walk in the open from the Makkasan Airport Rail Link station to the Phetchaburi MRT station. If you have heavy luggage on the way back, you can take a taxi directly to the Makkasan station to avoid the hassle.
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