Thai Airways Royal Orchid Plus - HKT-BKK

How reliable is the schedule in terms of what aircraft will be used? Does TG swap planes often?

TG switches planes a fair bit (as does CX, & others). You cannot be 100% sure what you will get until you board, although swap outs are not quite as rife as some would have you believe.

The domestic schedule doesn't suffer many a/c switches in my experience.

.....although swap outs are not quite as rife as some would have you believe.

I'm in agreement on this.

On most recent UA itin 2 of 3 segments had an a/c swap within 8 hours of flight time. I've never had that happen with TG.

i would agree that the chances of an a/c swap are low on this route. i fly it a few times a year. i don't think you'll get swapped from the 747 to the older A300. small chance you get swapped from 747-400 to the 747 all series. i try to avoid the A300 and don't really mind which 747 i get on that short route.