To ensure fulfilling stakeholder wishes, it is crucial to validate the documented requirements. This is often complicated by the fact that the wishes and intentions of different stakeholders are somewhat contradictory, which manifests itself in inconsistent requirements. To aid requirements engineers in identifying and resolving inconsistent requirements, we investigated the usefulness for manual reviews of two different model-based representation formats for inconsistent requirements; one that represent the inconsistent requirements in separate diagrams and one that represents them integrated into one diagram using annotations. The results from a controlled experiment show that the use of such integrated review diagrams can significantly increase efficiency of manual reviews, without sacrificing effectiveness.