This is a good
article on Wikipedia. But as some have alluded to above it does bull the regiment up a bit. I think they have avoided the budgetary axe because the organisation produce a good infantry man (comparable to army line regiments.) Also the RAF have had considerable political clout since WWII out of all proportion to their size or effectiveness. Look how many joint organisations are run by the RAF.
NB: As to effectiveness I was alluding to bombing not air-to-air. Nor do I wish to cast any aspersions on the bravery or professionalism of the force's members.