You summed it for me too Keith, and I suspect many other people who have been South on a contract that sounds scary.
For me it was a decision based on "Which might I regret more, not going or going and finding it wasn't what I hoped?" - so off I went.
I don't recall meeting anyone who actively regrets their time South though and the vast majority I've spoken with wouldn't go back and change it if they could.
In fact there's a guy I know at the moment who is considering applying to BAS, the main reason not to seems to be that he's fairly recently found a new girlfriend. It's very difficult for me not to say something along the lines of "Going South is a once in a lifetime opportunity, there's plenty of girls around and in 6 months time, the chances are you won't be with her anyway".