Does it feel rough on the adapter to body side or the lens to adapter side ?
I just tried 3 different Z mount lenses and then the adapter with an F mount lens. The adapter and the Z mount lenses feel about the same going on and off.
All 4 attempts were smooth with a minor increase in tension as the adapter was twisted half way on or halfway off. It almost feels like a spring pusing between the lens and body or adapter and body. Again, this felt the same on all 3 lenses and adapter.
If its under warranty, Nikon should exhnage it or replace it for no extra charge. Are you here in the US? Maybe policies are different in other countries. But reeason would dictate that if you buy something on sale and it doesnt work right, they replace it. Its not a bait and switch to make you buy something then upsell you on a non deffective item.
Thanks for the informative review. This lens is going to be a game changer in the wide angle arena.
We will be selling it on popflash.com
https://www.popflash.com/voigtlander-lenses/