The push for the M3 is about it being the standalone and also having the SW capability to be able to flash the CSL program, which, people seem to think is the closest to a motorsport program.
I think there is a need to use later variants, the sampling rate of the newer systems is higher, thus I would expect as good if not better than an early BMW system.
I have a later one from a mini, just not had time to do anything with it yet.