@JeffSchwenk - I'm the majority contributor of the KB for the heap size settings. It isn't automatically adjusted for you because doing so can potentially have negative undesired affects on the whole operating system. Back in the day of NT4 Server and early Server 2003, setting the Services heap size too high could stop Task Scheduler and some other built-in Windows apps and services from running. That's why you have to set the initial value and then ""tune"" it. And the initial value you set (2nd or 3rd setting) depends on whether you run as an App or Service. I suppose the Sage 100 Advanced (hah) installer could ask you about how to set it..
Going back to your question, for 30-users I definitely vote for running it as a desktop app, based on experience from many cases. Also based on technical reasons related to the MAS and ProvideX software architecture.