OK, i was about to drop my money on the Periodic Be. Because when modded they seem to become an altogether different beast, more balanced and kind of reference sounding (when you check the frequence curve below it imho goes towards reference when modded).
I asked a member here to make a comparison and how they both compete on the technicalities. Would be nice to know. My understanding is that the Be may be more coherent sounding due to a single DD and maybe have softer highs and a more natural timbre (less shiny/metallic sounding).
I have the hope that RAH has made improvements in this department compared to R1. So here is the comparison pictunre RAH vs BE (i tried to match the fequencies a close as possible):