I read the article about being less about free will and more about delayed gratification. Which seems ironic, since from a neural standpoint, can be one of the most addictive things possible.

Not really that compatible with free will in my view.

To slightly contradict myself, I don't think it's quite fair too say that the ability to wait for something can be an indicator of free will, since that characteristic can vary a lot, even among healthy adults. And describing some humans as having more free will than others appears very dangerous to me.