This chapter describes a comprehensive evaluation of ten enterprise reference models, including the models underlying the two leading ERP systems (SAP and Baan) and a number of prominent data model libraries. The main purpose of the chapter is to explore how well various model evaluation criteria and the associated metrics can be applied to real-life enterprise models. The analysis is structured into syntactic, semantic and pragmatic criteria. Not all criteria can be measured using clear or unambiguous metrics and some novel, exploratory approaches are suggested. The chapter does not only provide an insight how some of the better-known enterprise models compare against each other, but it also highlights the many practical problems and issues encountered with applying evaluation criteria to industrial-strength models.