I agree with those saying money is not everything - but it is a significant factor for most people and you certainly need to know what the deal is. Regarding the European base salaries, they are so tax-dependant that I would be loathe to state them here. There is no doubt the Portuguese salaries are the worst by a long way, although I am told the Barcelona deal is not too exciting either. Nonetheless, once you have done your penance at those bases you can move around to the better deals if that is what you want.
I particularly recommend blackred1443's post as being balanced and accurate. We have crazy roster disruption in the summer that BA guys simply don't get - it is a disgrace but we are on it with the Union. I have, however, pretty-well accepted that for the rest of my career July and August will be write-offs and don't expect much to change there. Ultimately we employ less pilots than BA so disruption kills us in a way it does not with them. Overall, if you are young and get into BA it would be a brave man who turns it down, but if like me you want to be home every night then we have a great deal to recommend us. The 5/3/5/4 pattern is also a huge plus that BA cannot offer. If you are fortunate enough to have the choice then you are blessed indeed.