Grayrivertech.com is the same company as Kowaritech.com and Avnertech.com. The good reviews here are paid reviews by the company. Check out their company details and address, it's the same ghost address (had it verified in London, office didn't exist) used in Kowaritech. They will take your payment, like they did with my US$500, and you will never receive the goods. Customer service disappears after your money has been sent.
Please stay away. SCAM!
They have been reported to Action Fraud in the UK. Help spread the news so that one gets scammed again.