If you just compare the patent numbers, Google got a better deal from strictly a numbers point of view.
Google: 12.5B for 25,000 MM patents --> 500,000 per patent
Rockstar Consortium: 4.5B for 6,000 Nortel patents --> 750,000 per patent
Of course, the question is, which patents will be worth fighting over ? It would interesting to see a breakdown by tech like 2G, 3G, and LTE.