389 is afaik full-featured enterprise LDAP server, so I guess the main difference is complexity. One thing to note is that there is also FreeIPA companion proje

389 is afaik full-featured enterprise LDAP server, so I guess the main difference is complexity. One thing to note is that there is also FreeIPA companion project for 389, which a bundles in kerberos, sssd etc that are needed for full auth set-up