LOL!
I play Genfu because I'm just very fond of the character. He is uniquely different than Ayane in the sense that their game design are opposities. One loves range, the other loves CQC. Playing both characters has allowed me to play patiently AND comfortably enough in both ranges, for both characters.
When I'm at a distance with Ayane, I'm totally fine as my spacing, my footsies. my fundamentals, and control of my character are all solid. I have the same feel when I play Genfu, and by knowing so much of their tools, I can play either of them wherever and however I feel.
Because I've played Ayane for so long (and watching A LOT of SSF4 tournament play), my footsies are very good. So is my patience, so I apply that to Genfu as well (I mean you can do this with any character as basic fundamentals are a universal sort of thing) so I don't feel like that I'm stuck with just a 66P or 214P approach with him. I just play patiently and see how soon my opponent decides to press a button when they approach, since I'm not scared of anything at a distance.
I feel extremely comfortable playing both Ayane and Genfu, so I find them both to be interchangeable for me, especially since both characters are very good and I have a high understanding of them. I just hate mirror matches (but who doesn't lol?).