Motion and collision sensing are done with a mix of good quality sensors, and then the algorithm that process the data.
The CF6's made in the last two batches now use the same sensor as found on the NB. Erv found it to be as good (and sometimes better) then the old sensor on the CF. They NB style sensor is also more readily available (and common parts are good for him, too).
So sensor wise, the PC and CF and NB are all very high quality.
What I don't know is if the algorithm processing the sensor data is the same and all three boards. I expect they are very close (and for managing micro-code, being the same makes life easier for Erv to program them).
In any case, motion sensing is going to be better then on the obsidian. The obsidian is nice (I have one!) but I wanted better, too. I have a CF6.1 waiting for me to install it on a new saber. It is the new style unit with the NB sensor.