Never had any issues with Air Asia. Have to be honest that as a resident in Bangkok I always fly with hand luggage only. This makes a big difference in the price. Don't see a difference between flying from DMK or BKK. By taxi both take about the same time to get to from Central Bangkok. Use my Priority Pass for using the lounges at the airport, so the obvious extra of being able to use the lounge when you fly with Bangkok Airways is canceled out.