I love the TCAS RA's reported in Class C argument; Leady how many were where a standard didn't exist?
I have had about 20 TCAS RA's reported to me in my career so far (touch wood), including a multiple event in a holding pattern, but not one of those was where a standard didn't exist. TCAS can be twitchy where rates of closure are high; particularly in the vertical plain where only 1000 ft vert is going to be used.
Sydney SID/STAR integration in particular has a TCAS RA happen once or twice a month (possibly more) just because of the rates of vertical closure; but there is always going to be 1000ft applied TCAS just doesn't know it.
Class E IMHO costs more than Class C; because it distracts ATCs from other primary tasks and costs RPTs more in track miles and/or changing vertical profiles away from CDA type flight. The only "winners" are the VFRs who now don't need a clearance from those nasty ATC who may ask them to fly somewhere away from there preferred course if they choose to give them a clearance at all... PS I've only said no twice to VFR aircraft clearances in 20 years, so I personally don't think there is any reason for this at all.
What role does the ICAO ATM plan have in Australian decision making (airspace design), are you busting your hump to position yourselves behind ICAO again? Don't for a second believe that airspace reforms are not included in Nexgen. Is Australia prepared to follow the USA all the way? Or are you just going to pick and choose again.
How are the characteristics going that have been implemented already? Merging target procedure and VFR on Top comes to mind?