The one they built on TechTV ran the OS but wasn't pretty in any way. If I remember correctly the logic board and power supply were from Ebay, processor was an upgrade, video card, memory, hard drive, and optical drive were all off the shelf. Then it was cobbled into an ATX case. I priced that kind of a setup and the total cost came dangerously close to a new (faster, better looking, and waranteed) Mac. It's something you do for bragging rights mostly--unless you have a lot of spare parts laying around.