Happened to come across the original article I was reading that mentioned the hummingbird:
Create your own GSM base station using the BeagleBone
You need to get the transmitter which adds about £400 on top but just think of the (illegal) fun that could be had intercepting everyone's mobile calls by setting this up without authentication, in the same way the security services (and increasingly the police) use the
Stingray.
I also remember reading that there was about 14 or 15 dollars or quid postage on top of the price for the Beagle, as well as not having the UK plug, which was another reason the NUC's seemed better value for some uses.