DCCD doesn't actually change the front/rear bias, it only changes the lockup. I want more rear bias in hopes of getting more throttle oversteer coming out of turns. The difference between 65 and 59 may be small, but I want to avoid doing anything twice, or wondering I should have done something differently.
I actually like the idea of a lockable open diff. I'm guessing that the open diff will help with the throttle oversteer that I'm hoping for. The helical probably responds a bit quicker when one end starts slipping, but that's a lot less important to me.