Anyway, I thought that the GPRS support is part of the OpenBTS development, and any hardware that can run OpenBTS is also capable of doing GPRS, but it is clear, that there are differences in the level of support, even between SDR like devices.
The majority of the code of osmo-pcu has been contributed by or on behalf of sysmocom. If you take a look at the development of the PCU for the last 6 months you will clearly see that sysmocom is doing all the work. Just like with OpenBSC a lot of others benefit from our work though. ;)
I still think that it would be nice, to clarify all this packet data related stuff on the site.