We are able to envision characters like Mr. Micawber, the unctious Uriah Heep, and Little Dora all too well, but by the end of the story we hardly feel like we know David. As Shaw noted, we know nothing of his political leanings, his unconscious desires or anything that is not universal. For the particular we must turn to secondary characters.
The masterpiece David Copperfield is imperfect, similar in the imperfections of Great Expectations: how it takes too long to dissuade Pip to leave Estella. But can we fault Dickens for this? I laughed, cried, learned new words, and generally enjoyed David Copperfield. The only faults I find I must try to correct in my own work. That's why I read all these works of classic literature.
Here's to post postmodernism!