PDFCreator Server: sever to user ratio

I've submitted something to support, but wanted to post here as well to see what feedback I receive.

We're considering moving from PDFCreator Professional to PDFCreator server. I'm curious about the typical "number of servers” to “number of users/endpoints” ratio to balance the load?

Ex. What's the threshold for considering additional servers? To get a idea of usage, last week our users sent 3448 documents (14427 pages) through PDFCreator Professional.