In an earlier paper [J. M. Cuschieri, J. Acoust. Soc. Am. 87, 1159-1165 (1990)], the coupled response of two identical plate structures, determined using a mobility power flow (MPF) approach is presented. The plates' responses are described in terms of the vibrational power input and transfer between the two plates. In this present paper, the MPF analysis for the vibrational response, power input, and transfer is presented for two coupled plates with arbitrary characteristics. Using the results from this analysis, a parametric evaluation of the plates' responses is presented for changes in the plates' structural parameters, which include different areas, thicknesses, materials, and structural damping loss factors. In the case of the structural damping, equal as well as different damping of the two plates are investigated. Furthermore, the response of the two plates for different excitation locations is included in the parametric evaluation. To minimize the number of results that are presented the source plate characteristics are kept constant except in the damping analysis. The results of the parametric analysis are used to determine the most critical parameters that influence the flow of vibrational power between the two coupled plates. The results obtained from the MPF approach are compared to results obtained using a statistical energy analysis (SEA) approach. The significance of the power flow results are discussed together with a discussion and a comparison between the SEA results and the MPF results.