I have no experince on australia, I have also wanted to come over since i was a child, don't know why it is one of them things. I am under no doubt that the grass is not always greener and there will be problems, i mean come on problems are caused by people and goverment which where ever you go will be.
When i say i believe the uk to be a dieing country i mean it like we have no industrial well very little left in this country, everything is imported so once our money runs out and importing goods are not cost effective anymore where will we be left ?, starting again ? thats my look anyway.
The other point i say try another state if that is an option is because i know reading on here one part of Australia is such a different way of life to another. That mixed with the feeling in the back of the op's mind (otherwise this post wouldn't be on here) if they didn't give it ago would the regret it for the rest of their life ?.
Life is short you need to do what makes you happy the question is, it better to regret the things you never tried or regret the things that didn't work out