As a sys admin in a school, Ninite is awesome. I really don't want installers and updaters popping up in front of small children and (often, technically illiterate) staff, and Ninite facilitates this. At the same time, it makes it easy for me to update software at a time to suit me - usually the holidays. The fact it denies Adobe the chance to trick me (or my users) into installing additional, unwanted software is a major bonus. It just means I don't have to visit users' PCs later to uninstall the crap.
(School Sys admin here too)... We don't use Ninite, but at my old job I looked at the implementation and liked the fact that you can have a local-central repository (This saves bandwidth and keeps things in our control).
It depends on the number of users, but I found it was very affordable for my network. I think it's less than $200 for the year. Beats using GPOs via Active Directory, visiting each machine in turn, or relying on users to do it (which is largely impossible anyway). The central repository is handy, but the software expires fairly quickly in some cases so it's most useful when I'm updating many PCs at once. If you can persuade your finance dept to fork out some money, I would recommend it.
