Andy
To amplify my point:
Replacing vast tracts of Class G with Class E will lead to an increase in safety (particularly when/if G loses DTI service.)
Replacing Class C with E, particularly those bits of C which capture RPT jet traffic, will lead to a reduction in safety - primarilly affecting those who pay for the system.
I am at a loss as to what economic or other benefit will be achieved by exposing a B747 on descent into Sydney, or a B717 climbing out of Hobart, to the possibility of unknown, non-communication traffic, where a full separation service currently exists.
I can honestly not remember ever having knocked back a clearance to a VFR aircraft. So the idea that this will introduce some new level of freedom for VFR users is difficult for me to conceive. What the new system (E relacing C) does is to remove a significant safety defence.
The workload for the controller will increase as they are now required to separate the IFRs, while maintaining a continuous scan for the unidentified aircraft which may just be at the 'wrong' level. This involves sifting through the clutter of all the low-level VFR in class G below. It also involves being ready for any avoiding action the IFR aircraft may have to take, possibly in contravention of its clearance.
Why?