That first example with 'eq is a little surprising to me. Previous to your post, I believed that Common Lisp symbols were equivalent to Lisp atoms. That is, I just thought of symbols as a way of interning strings (like Smalltalk, Objc, Ruby, etc.) ES6 Symbols reminded me of gensym. I didn't expect to see ES6 having the same behaviour as Common Lisp!

Thanks for posting.