Just purchased this from Newegg for $499.99 with no tax and free shipping.
You have to add to your cart for the $50 promo code to be applied.
Promo code expires 5/28/2018.
I see on forums that a recent firmware update has increased the refresh rate to address the flicker issues that earlier users were experiencing.
Decent reviews on Amazon, Newegg and YouTube.
I paid with PayPal in case I don't like it as they will apparently offset some of the return shipping cost. (up to $30)