I also not a guru but I've been locking on Ubuntu Core and it seems even more simplistic than Core OS. The great thing on Core OS is the etcd (for exchanging ke

I also not a guru but I've been locking on Ubuntu Core and it seems even more simplistic than Core OS. The great thing on Core OS is the etcd (for exchanging key values across clusters) and fleet (for managing e.g. containers on systemd and etcd). So Core OS has better management tools for things like Docker. Ubuntu Core is missing both parts and it seems better for embedded systems than for cluster management IMHO. And many people are using Ubuntu INSIDE the container. CoreOS is a good minimal layer... no need to have Ubuntu there... also Ubuntu Core does not have tools like apt-get ;)