I mailed Aaton for more info than the rumors and gossip going around.
This was (part of) their answer:
I'll not attend NAB this year and we will not show the Cantar.
The first official presentation will be in Amasterdam for IBC.
Every device had different latency.
If it would connect to the transmitter.
And if it would not freeze halfway the take.
We started to use it september last year and gave up after a very short period.
It was really useless.