Having flown alot between UBP-BKK and now PNH-BKK I can attest to the busing 'hassle'. Sometimes it happens because the flight is rather late and the plane won't be (potentially) used until later the next day. But I've also pulled into int gates on domestic routes and domestic gates on int routes getting bused. I guess that's due to the use of AB6 and 734 on the shorter less busy routes for dom/int (RGN, PNH etc).

There are two things at play here: 1) the hassle of exiting the plane and waiting until the masses fill up the bus 2) the ease of getting dropped off just below immigration/baggage.

Any time I can avoid the walk from A6 to baggage I'm happy though. Why is it A terminal is the only one (?) without a travelator heading back toward baggage?