I installed the transponder in the RV-9 this week and updated the Dynon's GPS antenna to the new -2020 model. Took all of 2 hours combined.
In the U.S., I am now fully ADS-B out compliant. In Australia I'm not. The difference? The U.S. Does not require TSO'd GNSS position sources for ADS-B out, they only have to "meet the performance requirements" to be deemed suitable.
How does this benefit safety? I am happy to fund the cost of ADS-B, for me, it was less than $1000 for a new GPS antenna as I needed the transponder anyway, but to only be able to use it, effectively, as a Mode C device only is maddening.
I have asked CASA what they need to approve the Dynon's GPS as a GNSS position source, but haven't got an answer back yet, it meets the requirements in their own AC21-45 so "maybe" they can be persuaded...