It is interesting referring back to the ATSB study of mid-airs, with regard to the angst shown about which frequency to be on at any given time or place, to see that radio use had little impact on the numbers, that the risk is greatest in or near the circuit area (understandably), but overall is extremely low anyway, and that, averaged out per 100000 hrs of GA flying to account for the vastly differing traffic densities, the much vaunted, proven, safe system used overseas results in a 5.8 times greater chance of having a mid air collision once you depart the circuit area.
Perhaps it's much ado about nothing.