In the USA they only have 1 flash and it is designed to suit unmodified CL9s. I think you will find something similar here - the junior burgerbasic flash will be ho-hum in outright gains (but you will get a different power delivery like the USA). So it will be an improvement but the car is likely to still run 15s over the 1/4.
The full Big Mac in Oz to get the 155+kw at the hub requires all the jtune bolt ons, intake, header, zorst, high flow cat, flash. That is why it is going to require quite a bit of money spent up front.