Just my two cents worth, I left BA in 2009 when the VR was on offer. It was primarily driven by the want to move back 'down-under' where I would be able to achieve a better lifestyle for my Family. I loved the flying with BA but as others have said it was quite hard hitting on my Wife considering I was away a lot. From a lifestyle point of view I have never regretted the move as I have gone to a job as a Training Captain on the A320 where night stops are quite rare, at times I think my Wife wishes I was away a bit more :-) I get to spend lots of time with the kids and my quality of life is streets ahead of what I could obtain around London or gain from a commuting lifestyle. The downsides are:
-Nowhere near the career path of BA, apart from checking I am as high as I can go, no fleet moves here, if I want to go Long Haul anytime in the future then I have to change airlines.
-Leave and days off are on a rotating system, no bidding whatsoever! So I have missed the odd important occasion due to no ability to bid! I have to take the kids out of school for most family holidays as you can forget time off during the school holidays.
-No other general perks, Staff Travel no where near as good (you will miss it!) No paxing in business class etc.... Standard of hotels and 'allowances' no where near as good.
Overall I am really happy with the move and from a family point of view would never go back (even if I could), it has come at the expense though of a career that offered stability and a great variety of opportunities! Everytime I see that BA tail in Sydney I do get very sentimental and generally annoy all my FO's telling them what a great time I had at BA.
By all means if you are going to prioritize family then a move maybe sensible but you will have times in your new job where you regret it! For me though the improved lifestyle was worth it.