Airservices do not have ab initio approach controllers (they tried once many years ago with limited success and decided to abandon the idea). Most approach controllers have at least 5 years experience in enroute before they go to approach. I am not saying the approach in necessarily more difficult than enroute, but from what I have gleaned from my colleagues who have made the transition, is that things happen a lot faster and you have much less thinking time. The experience gained in enroute is vital to this as you have already learnt alot about aircraft performance, communications etc. This may be where some of the RAAF issues come from.