I'm really satisfied with this desktop and the seller.  I'd been looking for a Small Form Factor (SFF) or mini desktop for not too much money, with decent storage, DDR4 memory and, ideally, NVMe capability.  The unit itself, as sold, had 16G of DDR4 RAM (which I upgraded to 32; max 64) and a SATA 1TB SSD (which I swapped out for a 1TB NVMe but kept the SATA internally as a second drive).I had an issue caused by a peripheral I added later that created some driver/bootup conflicts (not a fault of the computer but the external device) and wanted to reinstall Windows 10. Ran in to an issue with this, so I called up the seller STG (Skye Tech?) and they were super helpful. Full props to them. Managed to turn off BitLocker and run Macrium Reflect quickly and painlessly to clone the original disk.  The machine is blazing now, and I'm able to run multiple apps, including Python programs for data science, with terrific performance.  It was great out of the box too, even without my upgrades.The minor downsides of this purchase (and some suggestions to the seller, not necessarily drawbacks) are as follows:- Would be great if the Kingfast SATA ssd was just replaced with an inexpensive SP NVMe.  Given current prices, they cost basically the same while performance is about 10x with NVME (based on Crystaldiskmark stats)- The wired keyboard and mouse are basic and primitive (eg. no media controls).  For a few bucks more, they could have easily included a wireless set instead- the wifi dongle is not dual-band (ie. only 2.4G) and the bluetooth is a separate dongle,not integrated with the wifi.It all works even with the above, but again, minor changes would make major enhancements.  I spent just a few bucks and got the config I wanted.  Overall, great value purchase for a DDR4 NVMe 4GHz Windows 10 machine for under $200 (plus some nominal $ spent for minor personal upgrades, all relatively painless). Plus even more upgrade potential for RAM, disk, ports etc etc should I need them in the future.