Dick,
Class C is only the safest option if it is adequately manned.
The Aussie system of using a Class D Controller who sometimes is very busy to also be responsible for vast amounts of Class C airspace is clearly an accident waiting to happen.
You only have to see what happened at Hamilton Island where a Controller nearly put two RPT jets into each other, and hidden in the safety incident report was the fact that there are other people communicating. I also understand from locals that there were aircraft being held outside the zone.
I believe this is a clear example that if you load a Class D Controller with too much workload, errors can take place which reduce the safety in the D even though you have lulled yourself into a false complacency because we have lots of C above!
It's got nothing to do with the type of airspace. For goodness sake, the aeroplanes are still there, and what's worse, if it was E, the RPT would probably have to clog up the ATC airwaves self segregating with the VFRs buzzing about the place just outside the zone.
Have a go at AsA's airspace management; don't use this as a excuse to justify your beloved E. Make the C controller not release aircraft into the zone until the tower is ready for them.
You obviously think that E will magically make the VFR traffic go away. Well it won't, and how do you expect me to keep clear of it? Look out the window like some of the clowns above suggest? I really do not understand how people (they can't be pilots) honestly think that See and Avoid is still an option for RPT jets these days.