After upgrading to Full frame Sony Alpha A7 from cropped sensor Sony a6000 as a backup camera to my primary Nikon gears I was in a confusion state. I was thinking whether I should purchase all full-frame Sony gears or use NEX lenses in crop mode or get Metabones to adapt my Nikon gears. At last I paid my hard earned $22.99 for K&F Concept NIK(G)- NEX adapter and went out for Macro photography, used my Nikon 105mm/f2.8 Micro on A7. Results are awesome at least 80%. As there's no numbers on the aperture ring it's hard to know what could be the real aperture on the lens while sliding the ring on the adapter; I moved the slider 1/4 from the full open thinking it could be between f6-f9. But after checking in Lightroom I am guessing it was something like f13-f16, as pictures are bit dark.
After using it for couple of hours, I am satisfied with lens to adapter and adapter to camera connection, quite snug and no light leaking. full 5 star, maybe more, but not 5 as it's hard to know/guess the real aperture on the lens. But, I do believe after using it few more projects I would be able to guess the aperture of the connected lenses.
Adding couple of pics: Nikon Micro Lens with the adapter and a Macro shot using that lens on A7.