"Why would anyone retire before 55 having comitted to PAS and the new pension scheme, not sure I can see where this is going...."
Mate - you no longer have such an option - unless you want to be severely penalised financially.
I didn't think I'd ever retire before NRD. But by late 2002, I finally couldn't stand the way the RAF was going, so pulled the B&Y some while later after calculating the optimum date for pension and leave accumulation purposes.
At least that was an option I still had. You won't have that, I'm afraid, under PAS....