There are some top guys from BA here infinitely better qualified to speak on life there than I am. I can only speak about easyJet, and I really enjoy it. My doubt would be the work rate - it would be very hard to keep this up day after day for 35 or more years. I do training which adds a bit of spice and entertainment to the job but without that it could become pretty relentless.
My personal make-up is that I go to work every day determined to have a good day out, and I invariably do. I am not particularly bothered by late roster changes and I don't get too phased when I run an hour or so late - on that basis I am probably an ideal candidate to work for easyJet! Day-to-day, I thoroughly enjoy what I do. My observation of easyJet over the last few years is that, when I first came here, about 15% of captains in particular really hated the company. That permeated right throught the ranks and a culture of negativity developed. We then won a few significant victories in terms of our general working life, due to a combination of BALPA's efforts and a sensible management approach. Whether that sensible management approach will continue is open to question, but that is another story! Slowly but surely a new culture has developed where people just enjoy working here, and that has again permeated through the ranks. So whether you want to work here the rest of your life or not, the overwhelming majority of pilots like being here - that makes for a great working environment.
Most young folk are still going to go off and work for BA - but they will look back very fondly at a great time they had here.