The worst thing about Prestwick is the scramble and confusion of the boarding/gate process. When/if they sort this are out I wouldn't really mind the rest of the mess.
I cant cope with the scrum of 'desperate to board first' passengers hovering and being called for multiple FR flights at the same time, only to end up wating around in those dank corridors that they describe as gates. Its auful and I'm surprised there arnt pax who miss flights/try to board the wrong flight.
For that reason only I am happy to use EI to DUB or BD/U2 to LON.