It is the easiest to setup and understand really. There are no users, just hosts and their keys.
What it doesn't offer is a gui or tool to handle copying/installing/revocating keys so you trade super easy setup for a handful of nodes to management overhead if you are scaling up and down regularly.
What it doesn't offer is a gui or tool to handle copying/installing/revocating keys so you trade super easy setup for a handful of nodes to management overhead if you are scaling up and down regularly.