I am in the process of specing out a server that will do one task and have just a couple users. Between two and three users, with one of them being pretty much unused. It will be a security video server where the only users are actually using a viewer ap on their PC or a tablet/phone depending on their location. The software on the server side runs as a service and no one will be logged into the machine normally. Then there will be the two or three folks monitoring the feeds remotely.
My concern is that the server will be on a regular domain that is right at the 25 user limit (I'm not sure offhand how many actual user accounts we have today, but with admin/utility logins we're over 25). The Essentials machine is not being used by most of those users, nor is it going to be a domain controller, DNS server.... the ONLY thing it does is...