No firm views on this to a certain extent. I have had a nomadic career that has generally worked out ok. It would appear that some have entrenched views on the airline based oop north. I am biased for obvious reasons but being as objective as I can I would not choose BA over Jet2. J2 is a well run airline with 2 pay increases in recent month plus a small bonus for getting through the summer. Admittedly a no nonsense boss with Thatcherite views on unions but Balpa is hardly covering itself in glory particularly with the excruciatingly stupid rules on licensing post Brexit. Many brand new Airbuses on the way to complement a newish fleet of B737s and an admittedly ageing fleet of B757s winding down. Bases not generally stretching to the south except BRS and strong LGW rumours. It would not be a disaster moving to J2 unless you pine for long haul, bigger aircraft and jet lag. Good luck with your choices. I was many years ago in the left seat on a B747 negotiating my way around cbs on the South China Sea and deeply miserable with a perceived glamorous employer and associated lifestyle. I left and it all worked out in the end.