Ranked in these QuestionsQuestion Ranking
Pro Manages sudo permissions (root/user/none)
It manages sudo permissions (root/user/none) in a nice color-coded interface based on projects. You can manage more than one server in groups.
Pro Very reliable across multi-cloud and intermittent connections
A single self-hosted installation or Userify Cloud can manage your user accounts in multiple clouds or your own datacenter. All that's needed is HTTPS outbound from your managed instances.
Pro Installs instantly
The shim (their agent) installs in the blink of an eye. The server takes a lot longer (about five minutes) but only needs one command to install, so you can walk away and come back.
Pro Can handle tens of thousands of servers in a cluster configuration
Handles thousands of servers hassle-free using an AWS EC2 cluster.
Pro Built-in recipes for Ansible, Chef, Puppet, Terraform, Bash, and CloudFormation
Lots of built-in recipes make deploying pretty fast, and just adding a single server is pasting a one-liner that takes a few milliseconds to install.
Pro If central servers go down, you can still log in
Even if the userify servers go down, you can still log in with your private key.
Pro Available in self-hosted and Cloud, in single-server and clustered modes.
Cloud is available for free up to 20 servers, while self-hosted is limited to five servers free.
Con The Userify shim doesn't yet support certain containers
Containers that don't run an SSH server or non-standard useradd/sudo will not support the Userify shim. (Ubuntu-based containers, for example, work fine once you customize them with SSH and Python.)
Con Only up to 20 servers are free (10 on self-hosted)
Only up to 20 servers are free.