Vin,
My reading is that if you have accrued the 75 benefit which would allow you thegratuity before the point of transition and if you retire after it, then yourgratuity is yours - as agreed - when you leave.
If youreach the target for AFPS 75 after 2015, and then retire a little later, thenyou get the 75 benefits when you leave and the balance as FAFPS benefits andiaw those scheme rules.
But if not, then you have to tick the 20/40 box in order to get cash, or wait.