BrissyBoy,
I wouldn't listen to the guys controlling at the moment in regards to easily getting in as the interview has changed since they went through. It's now a behavioural interview.
I know a girl who just had her 2nd attempt at it and she is a pilot & still didn't make it through.
I am ex military and I honestly thought I had blown the interview, but luckily enough I must've given strong enough answers which suited the criteria.
There were no questions like why do want to do ATC & what do you know about ATC. They did however ask If I had visited a Facility.
The RAAF was great & I'd highly recommend it to someone who was say under the age of 25.
You just have to decide what it is you really want.