It was so trivial to terminate and restart dozens of servers at any given time since unless there was a mistake in the cloud-init, we could bootstrap our entire infrastructure from scratch within an hour.

It was amazing, never had to deal with something missing on a server or a config being wrong in a special case. Dozens of hosts just purring along with 0 downtime since the moment anything became unhealthy, hosts would start auto-booting and terminate the old instance.