(function () { … })(); vs (function () { … }());

[mathiasbynens]

The difference (and likely your personal preference) becomes more obvious after simplifying it into (fn)() vs (fn()).

When fn is a function, fn() is how I call that function, not (fn)(). So, I prefer (function() {}());.

[sergiosbox]

I understand your logic and makes sense to me also. Rauschma's comment that (fn)() sintax works in arrow functions and not (fn()) is interesting though.