I just wanted to post a section of my edition's introduction by Margaret Drabble, and see what people think of it (emphasis mine):

"Willoughby steps beyond the role of parody, and his final encounter with Elinor provides one of the most *troubling* scenes in the whole of JA's work. One would have expected the author to have dismissed Willoughby as decisively as she dismisses her other philanderers, the mercenary Wickham and the wealthy Henry Crawford (both of whom are allowed, of course, to have great charm). But Willoughby refuses to be distracted by Elinor's sense and Austen's morality and irony. He insists on being heard...his long attempt at self-exoneration is *oddly moving*, and quite beyond Austen's usual emotional range...(Elinor) listens to him with feeling, and her reflections on the injuries done to his character by 'idleness, dissipation, and luxury', 'extravagance and vanity', seem *conventional* beside the real pain and confusion with which he infects her...Her 'gentle counsel' to him seems *inadequate, even presumptuous*, and we are *relieved* to hear that despite all her common sense she begins to think of him as 'poor Willoughby'...The irredeemable and 'diabolical' villain has become, through the urgency of his emotion and the power of his presence, almost acceptable as a brother-in-law. One of the most curious features of this curious novel is the way in which it manages to suggest the power of the forces it tries to control and subdue. How intentional this may be, it is hard to guess: it is tempting to suppose that Jane Austen, like her spokeswoman Elinor, is a little carried away by her villain-hero, and cannot resist giving him better lines and better feelings than his conduct and his role in the plot warrant."