The C2 image takes 2-3 minutes to successfully boot up. The guys from #odroid (Freenode) suggested that this could be related to some Ethernet driver. And indeed the board does not get a DHCP lease. eth0 and lo interfaces are up.
Anyone else having problems with the C2 image / was able to resolve them?

Neither the Hardkernel Ubuntu 16.04 nor the C1 image (from this repo) had such problems.

EDIT:

Tried to debug this via UART: The last message which is logged to the kernel ring buffer is random nonblocking pool is initialized. Something which runs after that causes the lag.
I was also able to reproduce the issue with several different kernels, ranging from latest odroidc2-3.14.y (2016/11/20) to a version from early 2016.

Here's the full boot log: https://pastebin.ubuntu.com/23565023/