I just find it nicer to admin: things work the way I expect them. Two things in particular: I can configure FreeBSD jails easily and be confident in the security model, where Linux containers are just way too complicated if you want to run untrusted code. Second, systemd logging really rubs me up the wrong way, especially if something goes wrong when setting up a box.
There's only one thing FreeBSD can do that Linux can't, which is Capsicum that I don't use, but for basic sysadmin I just find it nicer. The only Linux technology I really miss in FreeBSD land is KVM.