Really, it's not so much a comparison as a complementary situation. I'm deep into two books that are incredibly different and perfectly suited to balance each other out, and both feature a pair of male-female twins as their main characters.
Gillian Flynn's Gone Girl is about Nick, whose wife, Amy, disappears on the morning of their anniversary, leaving signs of a struggle in their living room. His sister, Go (short for Margo, which nickname I seriously love), is one of the few functional relationships in his life. We watch the investigation unfold from Nick's point of view with a sour, hungover stomachache just from hanging out with him, and see Amy as a brittle, aggressive person. Then we watch their relationship unfold from the beginning through her journal entries and start to wonder if Nick is really the guy he thinks of himself as or the guy he knows the world sees. It's dark and makes you feel kind of hopeless about people.
Patricia Wrede's The Far West is the third book in the Frontier Magic series, and it's so exactly what I wanted it to be. We pick up where we left Eff--working at the college menagerie, living with her parents, everything going along. Her twin brother, Lan, is still living at home, and appears to be going through some real self-examination after the incident in the last book, but that's not what this story is about. The reason for reading Eff's story is that it's the story of a place and a time, and I wish I could find a book that did with real history what this does with alternate history. Her friends visit and pass through, she and the professors at the university try to figure out what's up with the medusa lizard they're studying, and Western expansion unfolds around them.
The Far West is a slow, easy novel that gets you caught up in the day to day. Gone Girl is a mover, grim and kind of icky, but fascinating. It's so perfect that whenever I need a break from one, the other is waiting right there for me. If you'll excuse me, I have some books to read.