The Grob is proof that the opening isn't as important as the skill of the individual players. Given players of equal strength, I think you would find the Grob has poorer results than in the usually unequal contests one usually observes.  When someone plays the Grob against me,  I assume my opponent is either very strong or simply arrogant.  Either way, I try to play sound chess without overextending myself, and usually I find out soon enough which one my opponent is.

I think the biggest hurdle the person facing the Grob must overcome is the feeling that he MUST win because of the apparent flaunting of opening principles by his opponent and realize that his opponent may be very booked up (as well as talented) and that he himself could easily be the one with the disadvantage.

Thank you very much, brilliant article, will study it fully in the morning!