Hi Craggenmore,
Here's my two-penneth. I'm a similar age to you and thinking along the same lines. Presently fly as Capt lo-co and wondering if BA will be a safer long term bet. As I am in Europe the pay difference is more or less neutral, but after a lot of soul searching I realise that you have to differentiate between someone who is below say 35 and someone older.
For the younger guys and girls it's a no-brainer, BA wins hands down. But beyond that it's not so easy (no pun intended!) One thing is certain, you can't kid yourself that a pay cut doesn't matter. Whatever you earn you spend / save and after the initial rush of the new job is gone one does miss the cash! (I took a big cut to move to my present employer, but luckily got promoted which made up for it.)
In the end though, you can only make the final decision once the offer letter is on the mat (or in the in-tray!).
Good luck with the decision and remember that the only one that matters is the one that is right for you!
KT