Chas, here’s a reply from a user that I trust on the Sony Vegas forum shortly after the version 2.0 firmware announcement. Sounds like the camera’s not ready for prime time yet 🙁
There is a visible difference between the 100 and 60Mbps on my AX100. Especially objects in motion look a lot better. Last year I filmed an eagle soaring and I can see that at 60Mbps the codec breaks apart.