I've been playing in my homelab in the past year with Illumos (OpenSolaris). After decades of using linux, everything is much simpler, all the linux constant changes are inexistent. Everything which was working in Solaris 10 (15-20y ago), still applies with small modifications today.

Has support for zones, which in my opinion are 10 steps above docker containers, has builtin ZFS support for root/zones/etc and so on.

Services are managed using SMF which has the only downside that services are configured using XML but usually if using only the builtin services it is not a problem. SmartOS also has a script to automatically configure the XML file.

I'm running OmniOS on a couple servers having a few zones each and I also run a SmartOS server for VMs. Launching a VM is a lot easier than on Linux. I can switch between Bhyve and KVM and use a single JSON file to configure all the VM properties and then launch the VM using a single command: vmadm create -f file.json.

All the networking is done using simple commands such as dladm and ipadm which are using the standard UNIX way.