What is the difference of a "Demo Unit" and regular unit?? I received one and just want to learn a little bit more about it. Which screen, CPU, PCIe card, is it supposed to have?? When I searched the Lenovo Support page and entered the model number, it came back as "not found". When I searched by the drop down menu, I found some with only the first five digits. I then looked in the HMM and I couldn't find parts assigned to it specifically. It is a Z61p 9452-J2U, in the manual I did find parts, except for the last two digits.

Thanks!!