Reasoning on use cases, this lens should be compared with a 600mm f/8: there's clearly a big size and money advantage here, even though the usual "equivalence" implications on DoF apply. I'd love to have it on my Sony E-mount system...
Sure, from the engineering point of view the Nikkor lens is much better - but don't forget that at the moment it's a one-of-a-kind thing, not the state of the art. I guess other manufacturers will go that way in future.
Sony a6300, Sony a6000, Sony NEX-6, Sony E 10-18mm F4 OSS, Sony Zeiss Vario-Tessar T* E 16-70mm F4 ZA OSS, Sony FE 70-200mm F4 G OSS, Sigma 150-600mm Æ’/5-6.3 DG OS HSM Contemporary, Samyang 12mm Æ’/2, Sigma 30mm F2.8 DN | A, Meyer Gorlitz Trioplan 100mm Æ’/2.8, Samyang 8mm Æ’/3.5 fish-eye II | Zenit Helios 44-2 58mm Æ’/2
Plus some legacy Nikkor lenses.
For size and weight advantages, I still have a 500mm f8 from Tamron and Tokina to use.