As Amy mentioned in the previous post, the Gone Girl novel was a gripping ride, even if it wasn’t high quality literature. I would say something similar about the film—gripping but, on the whole, not a strong film. Director David Fincher and screenwriter Gillian Flynn (also the author of the book) follow the novel’s plot line pretty closely, but the adaptation to film brings a few surprises. (For a plot summary see Amy’s previous post.)
As for the acting, Rosamund Pike turns in a superb performance as Amy (who bears no moral resemblance to my wife of the same name). But Ben Affleck’s performance as Nick seemed flat to me, lacking the emotional dimension needed for a character under such an immense amount of stress. This was just one aspect of the film that prevented me from fully entering into Flynn’s otherwise intriguing action mystery. A marginal script and numerous flaws in terms of realism were other features that pulled me out of Flynn’s world. 
But the most distracting thing of all was the soundtrack by Trent Reznor and Atticus Ross. In many scenes, the music was jarringly mood inappropriate. I liken film score composers to umpires in baseball. When they’re doing their job well, you don’t consciously notice them. It’s only when they fail somehow that their work intrudes on the viewer’s experience. For me, the Reznor-Ross Gone Girl soundtrack was definitely intrusive.
As for other flaws, in referring to them I cannot avoid giving away key aspects of the plot. So if you haven’t seen the film and would like to do so . . . SPOILER ALERT. The flaws range from a lack of plausible motivations for the characters (for example, what would motivate Amy to go to all the trouble to frame Nick for murdering her? She had nothing to gain—and much to lose!—in doing this rather than simply divorcing him) to the emotionally unbelievable (Affleck’s Dunne is not sufficiently angry with Amy after she returns home) to random unrealistic oversights (after killing her ex-boyfriend, which she made to look like self-defense, Amy goes to the hospital and is examined, but she leaves the hospital still covered in the blood of the man she murdered. In real life, don’t you think she and/or the hospital staff would ensure that she got cleaned up before she was dismissed?)
In thinking about all of these flaws of realism in Gone Girl, I was struck by the directorial inconsistency of failing in these ways and yet being so meticulously realistic with regard to the portrayal of sexual content and brutal violence. One pivotal scene at the film’s climax is so grotesquely graphic that even I found it appalling (and I’m not one to shrink at violence in films—Quentin Tarantino is my favorite director, so ‘nuff said there). I would like to ask Fincher, why be so excruciatingly graphic (I would say gratuitous) with the violence, especially when you maintain such a low standard for realism in other aspects of the film, some of which are central to the narrative? I don’t get it.
One positive thing I can say about this film, however, is that the southern detective, played by Kim Dickens, was not represented as a complete idiot, as southern characters in Hollywood films so often are. However, in the end, the detective does blow the case, so elements of the Hollywood cliché are indeed there, but at least she wasn’t represented as a thoroughly detestable hypocrite, so it wasn’t as bad as it could have been in this regard. And this is probably my prevailing thought regarding Gone Girl the film as a whole—it wasn’t as bad as it could have been. That’s about as much praise as I can muster for this one. Good riddance, indeed.