

I haven’t tried TrueNAS, but I use NixOS for my NAS and my other servers. It’s perfect for servers imo since it’s essentially a Linux system builder that you can customize to add whatever you want to your system.
The downside is that you’ll have to learn a weird functional programming language, especially when you get into writing service modules yourself (for services that don’t have an upstream module). And it’ll take some time to get familiar with it and learn how to effectively write your configuration.
Since you’ve used both, how do ejabberd and prosody compare to another? I was going to go with the former.