Those Prestege's on The Waggonway must be completely done in, even though they are 16 years old and should still have enough in them to be sold on.
They had a stint on the X30/X31 which is a pretty hard run, before the 28's - which as you say is a punishing route.

If you think that as airport shuttle buses in a previous life, they won't have lived the 'standard' existence that other acquired vehicles have had, before GNE got them either.
So after potting about terminal car parks and going back and forwards all day, they were certainly thrown in at the deep-end after moving North.

On a slightly seperate note, GNE must have been pretty desperate back in 2005'ish. Apart from these, Im pretty sure that was when they had a stack of vehicles on hire, as well as the ex-Arriva London, Nottingham, Isle of Man and Dublin deckers coming in.
The Arriva London Olympians didn't last as long as the others if I remember right, with them breaking down pretty regular. Can remember passing a scholars on the hard shoulder of the A1 one afternoon...