I've been running the free version of ESXi in my basement for years, and have been well served by it. One of the things that is always somewhat of a pain is patching.
check-soa is a CLI tool written in go which lets a DNS name server administrator easily verify that all servers listed as authoritative are in sync and serving the same zone by verifying the SOA record. I use this tool nearly every day at work to verify that changes have propagated to all slave nameservers.