I haven't read Freedom, but I did follow SEK and Scott Lemieux's discussion over at Lawyers, Guns and Money about the novel. And I was struck by Scott's observation by how the advance coronation of the novel interfered with his reading of it: "once you’ve abandoned the idea that Freedom is a Masterpiece of American Literachoor, it can be enjoyed as an engaging if very uneven minor novel."
I think the search for a Masterpiece of American Literature, or more specifically, the Great American Novel, is generally amusing. The idea that we have the judgement and foresight to know greatness when we see it, and to predict the longevity of any single work into the ages, is patently sort of silly. We can know if we respond to literature, if we think it's strong, but absent some sort of Harry Potter-like phenomenon, we can't know if something is important at the level of the culture. And even with a phenomenon like Potter, we just can't be sure that something will last beyond our lifetimes.
But more importantly, I tend to think America is too big for the Great American Novel to exist. Maybe the country was small enough once, though the divisions between New England, the South, and the mid-Atlantic were always considerable. America's essence is in its sprawl, its ungovernableness, its quarrelsome and competitive diversity, its flux and evolution. We can have a Great American Library. But any Great American Novel is bound for obsoleteness, for incompleteness.