HP Z210 purchased from Tekrefurbs through Amazon.Pros: Upgraded from my Dell i3 single core 8GB RAM 1TB HDD Windows 10 to the HP Z210 i7 quad core 16GB RAM 2TB HDD Windows 10. Loved the architecture as it is almost tool-less with rail clips for multiple HDDs and a side lever to open it up.Cons: I ended up buying and returning 3 of these keeping a 4th one because I loved the setup and I couldn’t find it for the price from another vendor.The 1rst body was scratched up badly with packing tape glue all over it. The DVD didn’t work.The 2nd came with only a 1TB HDD and no extra rail clips. When I accused them of bate and switch fraud and theft they said I could return it and they didn’t like my tone. The DVD didn’t work.The 3rd body and frame was so bent I couldn’t open it.The 4th had a minor chunk of metal sticking out from the back left corner that I filed down. So, I ended up keeping it as all else checked out. On this at least the DVD worked.All had obviously been dropped. Their quality control is atrocious. For these reasons I cannot recommend buying from these people.