Hello!
I just wanted to share some of my experience. I took the ACS in June 2014 and failed. I took a course for 2 weeks in March and then practised with a home set up.
I find quite surprising that not too many people share anything about this exam.
First of all for those taking it for the first time let me tell you that your nerves are going to be your worst enemy, if you're able to control yourself and be comfortable with being watched and judged as you work, you have won half the battle.
Another thing I wish someone would have told me is that, in order to pass, your work HAS to be PERFECT. Nothing else will do.
Realize that they want to pass the least amount of people (they cannot flood the market). So only the top of the batch is going to make it. Once again, your work has to be perfect, if you think you can pass with so-so work you are wrong. In the protocol you might get the impression that you have a range of acceptable work, but is not so. They are very nitpicky when they grade you.
I know people who worked really hard and still did not passed in their second time. For example one of them had 8 As and another had 9 As and somehow the rest of their work did not match the majority of their work. And one of them is going to appeal because she is sure that her work was excellent (enough to pass). I wish more people would voice concerns or complaints about their experience.
In my case I still have room for improvement. But I really wonder about the fairness of the process. Is it worth the money and the time it takes? I guess if you dont try you will never know.
Anyway, I don't want to discourage anyone, on the contrary, I just want to inform. Best regards.