Contrary to the name, their articles aren't book reviews so much as excuses to write solid, expert articles on topics that happen to be written about in recently published books. The articles are almost always interesting even when they are about books, because of their extremely high-quality contributors — Joyce Carol Oates, Tony Judt, Gore Vidal, Zadie Smith and J. M. Coetzee come to mind. They also publish lots of global, topical analysis. During the Egypt conflict of 2011-2014, they had some of the best coverage, for example.
I also enjoy the sheer lack of pretentiousness. They have world-class writers, yet they never seem full of themselves the way some other "liberal intellectual" publications (The New Yorker, The New York Times, The Paris Review, Monocle, etc.) do.
(Their book coverage is great, though. They also publish books, and are responsible for keeping a lot of obscure out-of-print stuff in print.)