Canonical has recently released Ubuntu 16.04.1, which is now considered stable enough to update from Ubuntu 14.04.04 LTS, and while I could do that easily on my main machine using update-manager, upgrading to Ubuntu 16.04 on Intel Atom “Bay Trail” and “Cherry Trail” devices is a bit more complicated if you need audio & wireless networking (WiFi/Bluetooth) support since the kernel needs to be patched, and on top of that recent Linux kernels are not stable on such platforms without some extra hacks.
Linuxium has done all the hard work, and created Ubuntu 16.04.1 ISO images for Intel Atom Compute Sticks with working audio, WiFi, Bluetooth, and “C-state” patchsets to avoid freezes. The images may also work on other devices, but this has not been tested so far.
If you want to give it a try, you can download ubuntu-16.04.1-desktop-linuxium-ics.iso, and flash it to a USB drive with Rufus (Windows) or dd (Linux) just like any other Ubuntu ISO images.
If you prefer different or more lightweight distributions, you’ll find Lubuntu 16.04.1, Xubuntu 16.04.1, Kubuntu 16.04.1, Ubuntu Gnome 16.04.1, and Ubuntu MATE 16.04.1 on Linuxium website.