Mercosur vs European Union?

[cadby]

I was wondering how similar the Mercosur policy of free movement for citizens is to the European Union policy. Do you need a visa to live and work in other Mercosur countries? Are special visas given to Mercosur citizens? Are they usually not refused? Are there different rights for citizens of different Mercosur countries, like a hierarchy? For example, Bulgarian and Romanian citizens aren't allowed to work in every EU country yet; there's a sort of embargo for a few years before some EU countries will open their doors to them. Are there countries whose citizens are treated similarly? Are you treated better than non-Mercosur citizens by immigration officials and immigrations laws?

Basically, how similar is it to the EU freedom of movement and what are the differences and complications? I know it's much more restrictive.