Anything over 30 I would head to VS personally for the reasons quoted above, unless you really want short haul. In that case, head to easyJet.
BA only really has 2 pros:
1. Job security. They're making cash hand over fist. (Ask yourself how... LHR slots (What happens if the 3rd RWY is approved). Old aeroplanes that are owned, but will cripple the airline if the oil price rockets as they'll suddenly need to invest in new airframes, but the production waitlist for 350/787 etc is long. And above all COST CUTTING.)
2. Variety if you want to try different places/fleets etc. (Already being long haul, Im sure you've realised that after around 4 years the excitement of visiting places for 24/48 hours soon wears thin)
VS pros.
Retirement bulge coming = Fast cmd, and increased seniority.
Better pay initially inc pension on flight pay.
Being at the bottom of a BA seniority list, looking at JSS coming in, ROTATING SENIORITY is a huge plus. This means at least every 3 months you'll be bidding at 33% down the list, getting some important days off. OK 1 in 3 months will be
, but in BA that will be 12 in 12 months. When you do get some seniority, it is still rewarded as your worst month will now be 88% and best 22%, BA every month will be 66%, just about starting to get some weekends etc.
750 Hours PA! Granted sims etc don't count, but as Wiggy mentioned, they don't really in BA either as we work to 1051 credit hours. For info, leave is only credited around 2:51 per day. So 14 days leave in a month leaves circa 48 hours left to work in 2 weeks, ignoring wrap days.
Ignoring all of the above, they both seem to have very different cultures. At the end of the day, you need to fit in. Are you Red or Blue?