Polarization diversity techniques have not received as much attention as others due to the significant difference in mean signal level between co-polarized and cross-polarized branches when one polarization is transmitted. However, MIMO systems where the multipath fading is only partially correlated could use polarization diversity to provide a high diversity gain. In this contribution, progressive (hue) polarization diversity performance for 3times3 MIMO systems under Rayleigh-fading environments is evaluated through simulations and measurements in a reverberation chamber. True polarization diversity was found to be as significant as spatial diversity at improving diversity gain, and hence MIMO system capacity.