getPosition() does give you the position in world space in both APIs and i'm not aware of any issues with it. I'm using it all the time and haven't had any problems. Maybe you can specify "doesn't work" a little more? Or can you create some test case where both APIs show different results?
public void setPosition(SimpleVector pos) { backBx = pos.x; backBy = pos.y; backBz = pos.z;}
public SimpleVector getPosition() { return SimpleVector.create(backBx, backBy, backBz);}