International Living, Marriage & Travel

So I'm planning to move to Netherlands in not-so-distant future, and I need some information on the healthcare system in the country. Does anybody here can help? I have some friends in Holland, and my cousin lives there, but I'm quite confused by what they've told me so far. It turns out that, despite their robust welfare state, the Dutch still are obliged to but a private insurance, and still need to pay straight out of their pockets when visiting a GP etc. but how burdensome are these fees, exactly? My cousin claims she's satisfied with the public healthcare (and she has two little children, so probably knows what she's talking about). On the other hand, I've heard several quite scary stories, like about a Polish guy who had to pay a 300 Euro bill for hospital stay after an accident at workplace, even though he had medical insurance at the time. I know that you can't judge a system by only few examples, but I don't really know what to think about this right now. I would appreciate if someone more knowledgeable enlightened me