Disclaimer: During the PSU supply crunch, I got a few "Ethereum PSU" from China.... until I get the EVGA-G3's and server PSUs.
So far so good but I am not very comfortable with the "poor man's PSU" so I use them when only needed and did not beyond 50% of the alleged watts rating. It however got all the cables, connectors required up to 6 x GPUs (6/8pins) or 3 x GPU (2x8pins) -- its the real deal.... but I don't recommend it unless you don't have any other choice.
Form factor on those "1800 watt" PS is WAY too small to be a legit 1800 watt - and I also find the "90 Plus" certification an issue, as there is no such certification.
They look suspiciously like the 1100 watt PS I have in some of my Innosilicon A2 units.
I'm not sure I'd trust them for *1* kilowatt 24/7.
The "1600 watt" PS are big enough they MIGHT be legit.