Does 3d gis provide a different insight than 2d?

The third dimension in GIS is popping up everywhere nowadays. When somebody sees a perspective (or even full 3D visualization) of 3D geographical data, his or her first reaction is usually very positive. However, after a second look or a longer work with the 3D GIS, the user sometimes realizes no or minimal added value, accompanied by unsolicited complexity caused by the need to handle 3D data on a 2D screen (or on some 3D portraying device in general). The contribution aims to present outputs from a deployed online questionnaire, which dealt with comparison of solving tasks based 2D or 3D visualization of data. Based on such outputs we provide several best practices examples consisting of workshops and tutorials, how to work with 3D geographic data, followed by examples of projects' outputs dealing with 3D geographical data. The pros and cons of such use cases are then discussed. We focused on cases where the use of the third coordinate adds value comparing to two-dimensional geographic data, their analysis, and visualization.