Well, one can always try to compare apple to apple NS vs. Zentyal vs. Univention as all seem to have a lot of features in common.
This makes sense, at least as end-user, depending on what you are looking for.
I’m running both Zentyal and Univention in various locations:
- Zentyal as simple & reliable “all in one IT box”. It just works (since they dropped Openchange and reverted back to postfix/imap mail) where/when needs are simple, without skilled local IT resources.
- Univention when more advanced IAM stuff is required (groups, distribution list, POSIX, Kerberos). Slightly heavier however and this requires, for day-to-day operations, to have better understanding of IT stuff like DNS content, DHCP…
I won’t compare with NS as I gave up quite quickly after my first tries to install and have it working.
NS looks closer to Univention, with potentially a lot of features while Zentyal keep it small and simple.
What does matter, at least to me, for this kind of solution, is that it works, just work, in a reliable and stable manner. This is much more critical and important than bells and whistles.