Argument visualisation (AV) tools enable structured debates around issues, positions and arguments. These tools have the potential to substantially improve transparency e.g. by enabling understanding complex legislation and debating. In this paper we present the results of the evaluation of an AV platform by experts and policy makers. The results suggest the potential of such tools is large particularly for understanding complex legislation and debates. The results indicate an AV tool can be also potentially used for massive deliberations when however usability is further improved. They further suggest an AV tool seems particularly relevant to the analysis and policy formation stages of policy making, where identification, elaboration and presentation of complex topics are needed. In this paper we employed a mature AV tool and concentrate on evaluating general aspects of such platforms hence we believe the results can also apply to other AV platforms.