Since I searched for a working OS image for the M3 and did found none here I stumbled accross Armbian. They have SSH enabled, M1/M1+ are fully supported and it seems they added Xenial support with their next release: http://forum.armbian.com/index.php/topic/881-prepare-v51-v201604/
If they provide Xenial next time I try to switch from Bananian/Jessie to Armbian/Xenial with my BPi Pro also 