Airlink is 200m from Phayathai BTS. I take a 65cm duffle bag. 10kgs carry on.
From Phaya Thai area be 1 hr in taxi and 300 baht fixed. Most taxis dont want to use meter to airport.
Taxi is 240 baht or 300 fixed. Takes 1 hour. Airlink 30 mins plus 5 to 10 minutes walk. 45 baht. Phayathai is handy to everywhere with BTS.
35 baht coffees there. Saxphone Pub nearby. Rangnam rd good food. Close to Pratunam and MBK.
KSR is not a good location unless you want Grand Palace or museum.