To compare the V2 against the D800 I post two pictures (100% cropped and SOOC) of the same object:
1) DSC_0505.JPG: Nikon 1 V2 VR 500mm f/4G @ 500mm, ISO 160, 1/2s, f/4
2) 800_7648.JPG: Nikon D800 VR 500mm f/4G + TC-17EII @ 850mm, ISO 100, 4s, f/6.7
The most striking difference is the much faster shutter speed of the V2 (due to slightly higher ISO and larger aperture), otherwise apart from the colour, the IQ of the two pictures is quite similar.