Update 2 (from one seriously unhappy customer):
Just got the machine back. Unboxed it and plugged it in and was greeted by.... nothing. Completely unresponsive machine. just a black screen, no BIOS POST or anything, not even a response from the keyboard (numlock/capslock). Boxed it backup and then will phone OcUK tomorrow morning. So far its been a month and I still havent got a computer back that works.....