I am a relational database programmer, and I am writing an application for a client who will have from 12 to 20 users on a network. Currently they are set up shared/peer-to-peer. I have been nagging them about getting a new server and to use a formal server OS. They called in a "Microsoft Certified" person who told them a peer-to-peer would be fine. But I really really don't trust that advice, as I have always heard that there is a 10 user max on a shared network, where all stations are XP Pro, and their current network performs very poorly. Do you know the answer to this, and do you have any recommendations, warnings, etc.
I suggested that since money is an issue, that they use Linux.