By Jon Cogburn
Slavoj Žižek has a characteristically interesting criticism of the version of object-oriented ontology in Levi Bryant's The Democracy of Objects HERE.
Graham Harman shares some preliminary thoughts HERE. Harman is currently writing a book on critics and commentators of object-oriented ontology called Skirmishes. It's currently slated to cover Tom Sparrow, Steven Shaviro, the Peters (Gratton and Wolfendale), and an appendix on Andrew Mitchell's account of Heidegger's fourfold. In the linked-to piece, Harman says he will publish a considered response, but it's not clear if it's going to be a chapter in the new book.