A mini unix server was set up for a client back in April 2010 and it has performed beyond expectations. At least the odd call or two, was expected, with connection or file access problems, but not one single call has been received from the client with any problems. It looks like these free unix systems are so stable that I can see why it is hard to find any companies that offer them, they have probably realised that they will not generate a lot of revenue when it comes to the support calls.
The server case is quite small and holds 4 drives and only gives out a minimal fan noise. Because their office is quite small, the size of this server was ideal, because it can fit behind one of the shelves on their desk as can be seen in the picture below of the server.

They have 2 Macs running OS X 10.5 and 10.6 and also a machine running Windows Vista and the three machines can connect without any problems to share their files. VPN software is also installed which allows the Vista laptop and the MacBook Pro laptop to connect to the server when they are out of the office. The DNS has also been set up so that they do not have to change any settings when they are connecting to the server from outside of the office.