To answer Berealgetreal's question. (Look away if you're not interested in Europe)
As far as I know, neither operator allows unions. There's a very big clue. Although, recently, Ryanair are making noises about permitting unions to negotiate. They had to. Norwegian hoovered up a lot of Boeing pilots and very few experienced pilots were interested to join Ryanair. Ryanair's original contracts weren't bad as you were directly employed etc. Now, you're self employed through a limited company that they encourage you to set up. So you pay yourself, your taxes, your holidays etc. You also pay for your accommodation when at the sim etc. Unfortunately for many pilots, the tax departments of several countries have become very interested in these arrangements and some pilots have found themselves on the receiving end of rather large tax bills. On the plus side, their training is good, equipment new and you'll gain a lot of hours quickly.
Norwegian has a similar set up. They use OSM and many contracts are located in Thailand. Since they've been expanding rapidly, opportunities have been available for fleet changes and or upgrades/promotions so the grumbling isn't too loud yet. See Terms and Endearments for more info.