I think Mr Tonks started this thread to get affirmation of HIS own decision. I have said it before and I'll say it again:
It's your decision to make, do the numbers and actually work out what you want from the RAF or your future career.
If you are reading this thread, you have time to sign the form (if you haven't already). The OTE paperwork didn't make it clear what happens if you don't return the form: automatic extension or automatic decline of the offer; who knows?
I, for one, declined.