I have to agree with a lot of what Yeovil said.
I am a 4 year DEP on the airbus/LHR, I've worked for other airlines before BA and its not all its craked out to be ...
Think very carefully before jumping ship ..... if you are say 35 joining BA on current figures its unlikley you will ever see ANY command. You will be around 3500, LHR shorthaul commands start around 1700 and gatwick 2000. Thats at least 1500 pilots to leave ahead of you, and with 5 years of no movement about to start due retirement to change to 60 it will be very sole destroying.
Another major issue in BA is that seniority doesn't only effect commands, BUT dictates your lifestyle. You WILL work every weekend being junior, you WILL do all the naff trips, you WILL work more days per month than more senior colleauges etc ...
Think VERY VERY VERY carefully WHY you might be leaving a smaller outfit to come to 'dinosaur BA'.
The SOP's issues are another topic in themselves ! But you get used to anything eventually, but it does hurt to know just how simple SOP's can be with other airlines, sadly many in BA have never seen anything else and think the SOPs are normal ... why, oh why does the non handling pilot operate the reversers ? If can be compicated BA will do it that way !!!