BAEF is terrible T&C wise, doing 5-6 years there while being good for the MSL position is going to be bad for your financial and mental health, especially if you need to pay SE UK rental/house prices for being down there...
Virgin wouldn't be a terrible place to be in comparison, and it has much faster times to command than BA for LH now (7-10 compared to 18+) that could be a huge advantage if you want to stay there long term. BA in comparison has terrible salaries for those who want fast commands. LHR SH takes Paypoint 11 to match a Year 1 WUK/EZY/J2 Captain. Paypoint 24/25 to match a Year 10/11 WUK/EZY Captain.
My order for you would be: BA LHR base, Virgin, BAEF/Norse at the bottom. (WUK currently pay better than BAEF, which is a bit embarassing)