Never trust anything that isn't peer-reviewed. These guys have been around for more than a year so if they're legit, there should be a couple of credible reviews about them.
In addition, they're everywhere which should've given them more publicity.

Try searching for gshenusa or gshenusa reviews, you'll see them in different forums advertising their site. Aaannnd I found an interesting thread: SPECIAL SALE OFFER ON CRYPTO MINING EQUIPMENT FOR HOBBYIST & INDUSTRIAL MINERS

And this is prolly them too, spamming on bitcoin.com forum: https://forum.bitcoin.com/post205055.html?hilit=gshenusa#p205055