Greetings, I am using the plain jane Ubuntu Core 16 image for Raspberry Pi 3 (stable) image on a 64GB microSD card (and a Raspberry Pi 3, of course). I've installed MATE desktop at the moment (might go with something else), and enough of X that I can use TightVNCServer to give myself a nice desktop ...

gratefulfrog -> Get the IP address for the device, and use that (don't try to use the DNS name). It's probably something like 192.168.1.x.