I don't have access to any drama cds but I do thinkg you make a good point about the differences between Naoe and Renjou. I find Naoe almost inhumanly suave and I attribute much of that to 400 years of worldly experience while your description of Renjou reminds me of Takaya when he only had 17 years of memories.

So it took Mirage 3 cds before they got the right cast? Well I'm very glad they found them since the seiyus are the best thing about the anime. Well for your sake I hope they continue the DR cds with a new Kei.