The real problem with your question is I don't understand it.

Can you please clarify. By definition (to some extent), in a client/server setup, no one is using the server, so it is MUCH more reliable and safer.
After many comments here (including yours recently), I have set up a "main computer" in my P2P network, and kept any users from using it. So it only serves as the AC database for the other networked computers. Didn't really notice a speed up by doing this, however. Thus, my question to you.
When I notice a real slowdown (in all the networked computers) is when we all are using the internet router to get on line for various purposes. Already have gigabit networking, except for the internet router, of course. Is that the bottleneck, or would setting up a server help?