Just correcting some misinformation on the net (attached images)
Gigabyte carefully avoided mentioning that their SSD M.2 connector was on the back of the GA-z170n-Wifi motherboard.
But it backfired. Commentators looking at photos of the front of the board can't see the connector and think the M.2 connector which holds the Wifi card can be used for SSD if you take the Wifi out (I don't think it can be used for SSD)
The correct M.2 for SSD is on the back, as the pictures show. (It can take PCI-e storage instead of SSD if you've got the money)