It's true that some of our guys are being offered a griffin course at the end of 705 SQN, instead of going on to holdover on a ship or be teaboy to an admiral whilst they wait for a course spot to become available. The Jury is still out on whether or not this is a good deal!
It means voluntarily doing ANOTHER ab initio (3 strikes and you're out) course, at the end of which you go to learn to fly Seaking J's which used to be pingers and are now utility only. There is no chance of any of these ab initios being trained up as SAR to join 771 because that is still a "grown ups" job in the RN so if they want to progress they'll have to apply later for a junglie, lynx or Merlin conversion course.
On the upside you keep flying! Shawbury is in a nice part of the World! I have it on good authority that the Griffin is fun to fly!
I reckon you're better off poking off on holdover for a year to wait for the course you initially wanted! (Like I did!) I'd welcome an alternative view!