I already owned a Z620 before and this is one impressive workstation computer so naturally I wanted a second one to replace a failing desktop computer. The one I received Stallion Tek was as clean and as pristine as the first one I had bought from another vendor. The word on the street is they are seeing a second life after being used as servers for Facebook. These are big, powerful machines that cost ten times more when new and the dual processor and multiple-cores combined with the copious ECC memory make them ideal for video (Adobe After Effects is a killer) and 3D rendering such as Poser or Daz3D or as a gaming machine.They are modular and the system construction is very robust reminding me of the old Apple G4's in their quality build. Sadly, I do not see a successful Hackintosh build for them, anything to replace those Apple trash cans for video editing. That said, I am fine with using Windows 10 Pro and had an old license lying around that I repurposed for this workstation.Also, since they are older you are not installing NVMe without some serious BIOS gyrations. When you install your SSDs you can use these caddys to fit in the drive bays: B00F3QFKNS. For gamers adding your video card such as a 1070 or 1080 is no problem, the power connectors are tied down but the HP graphics 6-pin power connector is a bit more robust and a dual card install requires a special connector. There are plenty of threads on this issue online and some people even try to install three cards.The best part is the copious fans are very quiet. The only downside to these boxes is that the dual Xeons don’t exactly sip electricity when they are going full bore and they do throw off heat! Frankly, once you run a real workstation you’ll find it hard to go back to a consumer grade desktop.