The bare-bones Shuttle SN25P PC provides a strong foundation for building a midrange, small-form-factor PC, but the overly complicated CPU fan and heat-sink design might annoy you at certain points during installation.
The Shuttle SN25P features a relatively straightforward design for a SFF system. The removable drive cage gives you room for one optical drive and up to two hard drives. An 8-in-1 media card reader is included with the kit. Underneath the drive cage is the CPU heat sink, the fan, and a plastic shroud for funneling hot air away from the chip. The cooling hardware is sufficient, but in order to actually install the CPU, you have to remove all three parts. It proves to be a difficult process because the plastic shroud that directs airflow requires brute force to remove, increasing the risk that you'll break off one of the little tabs or posts that secure it to the system. At least the internal cables are generally well routed, making it easy to connect your hardware and ensuring clear airflow through the system.
The SN25P comes with Shuttle's own FN25 Socket 939 motherboard. Built to Shuttle's own specifications, the motherboard has support for one x16 PCI Express graphics card and a separate x1 PCI Express expansion card. You also get two memory slots, so it would pay to know how much memory you'll want from the start, because in order to upgrade after installing your first pair, you'll need to get rid of at least one original memory stick. This sort of limited expansion, however, is typical of all SFF systems. The motherboard lessens the need for expansion by including an integrated Gigabit network adapter and an onboard audio chip that gives you eight-channel analog output, as well as a separate digital out.