I think that x-fit guy is right.
I am a medical doctor with an interest in biochemistry and I have followed with interest the last couple of decades the effort of the market to push some product for runners that will make them "better" in some way.
So far the industry has simply failed.
It is the same story with diets, weight loss and health in general.
And still, we, the western people, refuse to accept what seems to be the truth about nutrition (for better health or improved performance).
That less is more.
Only after several deaths did we start to accept that you cannot (should not) drink over your thirst. That electrolytes consumed during a race will not change the concentration of them in the blood. And one of my favorites, the recent news (few years now) that the body absorbs nutrients for about 40 minutes after exercise. Like the body stops absorbing nutrients at some point. Like the cells stop even for a milisecond the thousands of reactions that deal with energy and energy production or proteinosynthesis.
Most people here are much better runners than I am. And this is not because of some juice or sugar or superstarch or protein that they consume.
As someone else much wiser said there is no superfood but there is a super diet. And in my humble opinion it is not produced by companies but you could find it in the humble table of your grandparents.
So please keep your hard earnt money, there is no need for special foods and drinks.