Lots of falsehoods in this thread.
Okay, first off, the nano always outperforms the 980.
Next, the nano doesn't get thermal throttled. Short of removing the fan that's rarely going to happen. The nano has a different type of throttling from the 980/all other gpus: Power throttling. Not heat.
When you overclock a normal gpu, you increase its performance by increasing its core speed. With a nano, you increase its performance by increasing the amount of power it's allowed to draw.
At the same price range, the nano is the better pick over the 980. That said, in the USA, the Fury is available for the same price as a nano and slightly outperforms it, making that the best choice.