I agree with what Chugalug said. I extracted myself recently from the RAF; I took a chance and left early (pension intact). Rather than thinking about leaving for one specific opportunity, think about the wider opportunities available. It's just one offer you've been made and there will be others. If it's stability you're after then it may be worth taking the plunge. I pulled the pin with no job in mind and it worked out well for me. It might be the case that the current offer might be still on the table in ~7 months time.
I think there has to be grounds for staying put in your last 12 months when you PVR. I would kick and scream like hell to stay where you are - plead family stability, house purchase, kids in school, wife's career, anything to allow you to stay in location and avoid a right good grafting through a 4 month posting.
even if you do get posted (utterly asinine) you should be entitled to at least 90 days notice, and if you're clever you'll be able to make your resettlement etc. make about 5 months which means you'd only have 4 months actually away from home in a ridiculous posting.
So, ask yourself if leaving is about this one job or is leaving what you want to do?
Personally, I've never been happier since walking out the gates. I got a hefty pay rise and pension in pocket, more freedom, more responsibility and no bullsh1t.
Best of luck with whatever you choose....
H
(edited to add - there are several ways to navigate the not working on GRT)
Last edited by Herc-u-lease; 26th Apr 2015 at 20:50.
Reason: addition