Roger,
During my training I did look at the REX cadetship and even did the WOMBAT test; found the test to be fairly straight forward with it testing your hand-eye coordination with you chasing a chasing a ball with a joystick in both of your hands, various games to play as well and some simple straight forward maths. I did successfully pass this test bearing in mind I did no practise for it before attempting it.
In terms of the Cadetship a really close friend of mine did get through all the stages and was offered a place. He swears by the program and is absolutely loves being on the SAAB with him meeting great people along the way. BUT it is a major financial decision so bear in mind the costs and do ask HR questions regarding their contracts.
As I am aware the $25k you pay upfront covers accomodation (YOU only) and food while training in Wagga Wagga (I could be wrong) but you'll be contracted for minimum 7years, if you don't serve the 7years you pay back for the training costs incurred.