I will try to bite my tongue, since if I get started, I will sound like one of those US expats that want to run the country down.

But, suffice to say, the US is wildly over-legislated, and I don't put a lot of trust in the US immigration department.
My husband came to the US on a fiancee visa, and even though I was a sponsoring citizen, we still had trouble (they sent my husband a green card and work permit...one year after it was due, and after we'd already left the states since he needed to work). I really believe they have a 'no admissions' policy for South Africans or something.

My sincere advice would be that if you go to the US, make sure that you keep some back-up funds and have a plan just in case you should need to leave, because many people have difficulty.
I'm not feeling too good about those FEMA camps that are sprouting all over the US (for the good or detention of who, nobody seems to know), or about the fact that Obama seems to be a man with no past and questionable ties (and I did vote for him...but have lost faith in him these past few years). The Tea Party, the liberal vs conservative extremism (both are pulling further and further extreme), the economy (will probably pick up, but at who's expense?), the big business lobbying, the Patriot Act...
My two cents...despite all the "freedom" rhetoric you will hear in the US, countries like NZ and South Africa are far more
literally free than the US. Honestly. There is a lot less legislation, which means you are more free in countries like SA and NZ to manage your own finances, move around, live where or how you like, start up a business, etc.
Despite that, the US is a large and beautiful country, with huge diversity, and traveling through different states is an experience. You can buy practically anything, and find people from all over the world who share a common ideal of having a better life. It can be a wonderful lifestyle if you have a decent salary, especially if you focus on the moment and try not too think too much.
