OPC UA is one of the most prominent candidates for a middleware in future CPS scenarios. It provides many concepts which makes it very useful to address challenges in the area of flexibility, security and availability. It offers a semantic rich information space with extensible OPC UA information models. They make it possible to develop smart client application with a high degree of flexibility. This paper summarizes experiences made with the use of OPC UA information models. Thus, it presents various projects in which we used OPC UA as base technologies. Then, we describe how information models supported the development. On the other hand, we provide a list of issues which we experienced regarding this information models. There is some potential to improve OPC UA in the area of revision management and distributed applications.