To what extent should we use ES6 features in our node modules?

Now that the stable version of Node has moved to 4.2, we can use ES6 features like classes and generators and plenty of other stuff in our node modules.However to add them would mean excluding people using older versions of node. What proportion of users do we think have moved to the LTS version (4.2)? Might it affect the popularity of a module to limit it to a node version like this?

Submitted November 21, 2015 at 02:09PM by TMiguelT