As for CAD work, I prefer to suggest you check the immigration website of AU to make sure if there are relevant skill worker information.
I ever traveled to AU 1 year ago. Everyone can has his opinion about this country but as far as I can contact, I think in general AU is a beautiful land full of amiable people in spite of few cranky people.
You will find that the life in Australia (not sure about NZ!) is quite slow compared to much of the world. This isn't necessarily a bad thing, as we are generally quite relaxed and laid back. Even "big" cities like Sydney and Melbourne don't really have the cosmopolitan beat of New York etc but are sufficiently large and have plenty of things to see and do. I think it has to do with our isolation from the rest of the world, the very very very low population density, glorious weather and landscapes.
One of the biggest downsides of living in Australia is the cost of living. This is a result of both a stubbornly high Australian dollar, and the extra costs associated with our isolation (eg. transport).
Having said that, it is home to millions and millions of migrants and we are all generally very happy here :)