As a key element in the Model-Based Enterprise (MBE), the Model-Based Definition (MBD) enables the use of annotated 3D models as sole carriers of product information, a practice intended to replace (or at least minimize) the need for traditional engineering drawings. Although both academia and industry have emphasized the benefits provided by MBD, little empirical research has been conducted on the use and human interpretation of annotated 3D models. In this paper, we present a study where annotated 3D models were compared to conventional engineering drawings in terms of efficiency (defined as the accuracy and time to find information) and cognitive workload. Our results show that there are no statistically significant differences between the two presentation formats. Annotated 3D models are a valid alternative to traditional drawings to effectively communicate product information, but their primary value may not be in terms of human interpretation, but in the automation mechanisms that can be enabled by the format.