I'm not convinced that a salaried PhD would be an advantage. Is there not something rather bizarre about the government taxing the money it's giving to you to support your studies?

I'm not sure how it works in the Netherlands, but in the UK you can claim unemployment benefits without having to have been paying taxes (so far as I'm aware). Surely people applying to PhD positions aren't so incapable of managing their finances that they require payment monthly rather than quarterly? That's the only difference I can see between a grant system and a salaried one.