I don't know if any of the dating sites they reviewed use a similar system to OkCupid (users answer questions and also pick how they want matches to answer those questions and how important they are to them,) but I don't think OkCupid was included in that study. The author wrote that the matching algorithms of the companies they reviewed are proprietary, and were not shared with the researchers, but OkCupid's matching algorithm is publicly available.