Hardkernel ODROID-C2 board is getting some direct competition with FriendELEC’s NanoPi K2 development board powered with Amlogic S905 processor with 2GB RAM, a very similar form factor, and many of the same features, which together with Khadas Vim (Pro) brings the number of low cost Amlogic based development boards to three.
The main difference with ODROID-C2 is then the presence of a Wireless module. NanoPi K2 form factor also matches Raspberry Pi 3, so many – but not all – accessories designed for Raspberry Pi boards should work on the board. An Android 5.1 image is provided for the board, and later an Ubuntu image will be released too. More hardware and software details. including instructions to build from source (U-boot, Linux 3.14…) can be found in the Wiki. So Hardkernel has clearly an edge here, with Ubuntu 16.04 with GPU and VPU support, Android Marshmallow image, and several community supported images. Since the boards are so similar, I’d expect the software gap to narrow over time.