I have used one of the cheaper Airhawks for several hundred thousand kms on GS's, and find the lighter models wear very well. I don't reckon you need the heavier model.
I have seen one where the metal valve has rubbed through the outer material, but a bit of rubber bicycle inner tube wrapped around the valve will prevent this.
They should be inflated very lightly, so they are enlarging the area of contact only, not holding you up off the seat.
They add at least 200kms to what my backside can stand in a day
Haven't tried it on my new CT yet,