Peuce, you give a link to the ASTRA document. This is valuable, however I note that the ASTRA document is based very much on the FAA cost benefit study for ADS-B, which states:
Of the safety benefits, the single biggest was CFIT prevention
The problem here is that the original FAA study linked CFIT prevention with the installation of the Capstone Project in Alaska. As we now know, aircraft are being fitted with Enhanced Ground Proximity Warning Systems quite independently of ADS-B, and this is what will happen in the future.
I believe the FAA paper needs to be reconsidered by separating CFIT prevention with the other benefits that ADS-B gives. Then we will be able to get a true and genuine cost benefit study.