The other point is that BA FOs are given somewhat more autonomy in how they run the operation on "their" sector than at EZY (this has changed a bit since BMI merged due to their autocratic approach to CRM).
You can do as much or as little as you want, but in general you can choose fuel, brief the crew, handle the tech log, liaise with ground staff, do all on-board PAs, autoland, park etc. Training co-pilots, management opportunities, sim stand-ins, technical roles, recruitment etc.
Briefing is easier - we don't labour our way through every waypoint on the SID but instead focus on the specific threats of the day - and most Captains are pretty easygoing.
But... (and it's a big "but")
Heathrow stinks. The crew car park is full. The buses don't run often enough. You're nearly always holding. Stands are frequently occupied, or lacking someone to turn on the guidance or position the bridge.