Well, 5 Herc loads. Carrying over 100,000lbs of freight direct 4500 miles perhaps not quite so limited. Max range over 5500 miles without refueling - we run out of crew duty before we run out of gas etc etc.
It is indeed the dogs bollox and does "exactly what its says on the packet". Shame the same can't be said of the J model. Have you got your yokes to fit back on yet?
PS C17 has always been Cat II.