Quokka,
Yes, I do accept that. The problem is that a certified ADS-B unit does not exist at the moment whereas MSSR, mode C transponders and TCAS exists at a present time and are readily available.
I see a plan here for Airservices to constantly support a system that does not yet exist, rather than take the safety advantages now of the highly proven present system, and then move ahead with the better system, when decisions have been made in leading aviation countries where the equipment is proven and certified.