7/4/14 update: I had three 1g survivors from the root cube experiment. This winter I sold one, but that one died frozen in transit due to USPS losing the package for nine days... So I sent a replacement in May leaving just one survivor from the 6 root cubes, and the one grown from a full cutting (let's call that one BM1).
But that survivor is now larger than BM1 side by side, and has two healthy vigorous shoots. Here it is side by side with BM1 (she's the one with the purple fruit.)
Now, in BM1's defense, she's been growing fruit all year and that takes a whole lot of energy. But the survivor is grown from 1/6 the amount of wood BM1 is grown from. It is worth noting that this survivor was the shortest of the three I had.
So I think by now it is fair to say that the node cuttings in rock wool grew more tree faster than the one grown from the tried and true root chamber method. But the rooted cutting is much thicker and fruiting. At least for now...