The listing is a bit weird though, it seems to suggest the GTX 1060 with 6GB GDDR5X has the same specifications as the regular GeForce GTX 1060. That doesn't make sense as it would be very odd to equip the card with more expensive memory and then run it at exactly the same speed.
According to the rumor mill, the GeForce GTX 1060 with GDDR5X memory may actually be a cut-down GeForce GTX 1080. I guess we'll find out more soon, but this could be a model for select markets like China.