The machine itself is amazing (I basically agree with all the excellent reviews of the performance (in this thread and everywhere else), but I found that the physical build quality (outside of the metal parts) of this thing surprisingly terrible.
Plastic for RAM sockets? I can never understand why they decided to do this. Even the standard RAM sockets that they have in MacMini/Macbook will work great (with the metal clips), but no, they have to make it all in plastic. Thin, easily broken/bent plastic, too.
The metal body look great and solid, but then you open it up and found cheaply looking things in there. It was such a turn off. The unit that came through my desk a month ago, had a malfunctioning RAM socket, in addition to the socket being bent a little so it's skewed/uneven at the top. It looked really bad, and on top of that I had to return it right away to have the broken socket repaired (it won't recognize any RAM stick being inserted there).