Ranked in these QuestionsQuestion Ranking
Pro Docker pre-installed
Docker comes out of the box.
Pro Automatic updates
Automatic updates means better security and reliability.
Pro Built on systemd
Uses unit files for managing all services and journald for logging.
Pro Great documentation
Has guides for installing systems like Kubernetes, setting up etcd, and using cloud-config to manage hosts.
Pro Very lightweight, smaller attack surface
The OS is tiny and has a much smaller attack surface compared to other distributions.
Con End of Life May 26, 2020
Fedora CoreOS is the official successor.
Con No package manager
CoreOS has only the minimum for being a host. It doesn't even have a package manager. Alternatively you can start a container with any software you need.