The document discusses building a DIY router using the open-source Vyatta distribution for several reasons including cost, performance, and fun. It recommends using a low power mini-ITX motherboard to save energy and lists the power usage of some example routers. The author's DIY router uses a specific MSI mini-ITX motherboard with network and storage components. Vyatta is chosen as the open-source distribution because it is Debian-based and open-source, providing a standardized management console. Setup instructions for Vyatta are provided.