All three have big issues - for a start, none of them will commit to allocating a base until you finish training, which is appalling; they know where the slots are available and so could recruit for bases, but their attitude is that we should be so pathetically grateful to earn them so much money that we should be willing to take the lottery on being based on the wrong end of the continent away fro family. If that isn't a big enough indicator of their contempt for individuals, then the fact that all three will take you as a contractor rather than employee, thus compelling you to fly when ill and never challenge any order because you have no employee rights or protection should ring alarm bells. AT least NAS and EZY have union systems, which is why their conditions are better, and the Norwegian union seems pretty tough too, unlike the scared BALPA pussycat.
In a nutshell, keep away from Locos if you can, though admittedly they are better than unemployment.