One journalist compares the strategies and platforms of Sanders and Stein in this article. More information about Jill Stein’s platform can be found in this article as well. I think as voters we need to be as educated as possible to make the best decision.
While voting 3rd party may not be the most popular decision, why vote for the lesser of 2 evils when you could vote for your favorite option, whether it be Libertarian Rand Paul (who I hear is now dropping the campaign), Green Party Jill Stein, or a mainstream Democrat or Republican? The point is, as citizens of the United States, it is both our privilege and our duty to vote for candidates whom we feel most accurately represent US. Only then is it truly popular representation.