In the present study, we employ a set of different sulfur-nitrogen compounds, which contains eight different SN bonds of varying polarity, to study descrepancies between experimentally and theoretically derived electron densities characterized by their topological properties at the bond critical point according to Bader's quantum theory of atoms in molecules approach. First, the convergency of the computationally obtained parameters with respect to the theoretical approach (flexibility of the basis sets, method of computation, influence of substituents) is presented. A comparison with the experiment is performed by a direct comparison of the theoretical and experimental counterparts and by an investigation into what extent the various data sets exhibit relationships to the nature of the bonds. This approach allows testing of the self-consistency of the theoretical and experimental data, respectively. Finally, the outcomes of the atoms-in-molecules approach is compared with results obtained from the natural bond orbital approach and natural resonance theory.