GOAT response. You are like a politician!
But Murray is better than Del Potro.
But why am I like a politician?
And Murray might be the better player right now definitely, but not the greater player overall, he will only be that if/when he gets his maiden Slam (assuming that happens before JMDP wins more).
US Open seems the only slam tailor made for him that's the problem. If he doesn't break through beating a top 3 or 4 player in New York in September, where else will he? AO is slow and favours grinders, RG is Rafito's backyard and his grass deficiencies were exposed by Ferrer.
Roland Garros is actually a better surface for him than USO imo, he has played some of his best tennis there. That he has a USO title and not a FO one is purely down to circumstances - getting a bit lucky vs Federer in USO final and unlucky/poor fitness in FO semi basically.