We have applied a novel approach for the critical assessment of vibrational maps that are used to parametrize the local-mode frequencies and coupling constants that enter vibrational exciton models, which are in turn widely used for the simulation of biomolecular 2D-IR spectra. We have demonstrated that a localization of normal modes can be used to extract local-mode frequencies and coupling constants from quantum-chemical calculations, which can be directly compared to those predicted by vibrational maps. This makes it possible to assess the accuracy of the different ingredients of vibrational exciton models, which might be masked in a direct comparison of predicted spectra with experimental data.