They are very similar, I have both. Gun to my head, no, you don't "need" both. CB slows down sooner and is better on flatter stuff. DD is stupid good, seems like this ball speeds up sometimes going through the pins, reminiscent of the silver streak pearl.

Northface,

if you had to choose one, which would it be?

I want both, want the DD because I haven't tried Roto Grip since the original cell.  the Code Black just seems like it might be a ball like the hyroad, too good to not have

Have the CB, it's everything they say it is. Quickly became ball of choice for me. It replaced the IQT30 in the line up. Bowl in 2 centers every week and it has performed well in both. One of them being wood and plays dry, the other newer synthetics that are med. I don't have and don't plan on getting the DD but what I have seen in person it looks good. CB plays less than my SLOCK but more than Hy-Road Pearl.

Code black plays less than my Snap lock but more than Hy-Road Pearl.

Yes...This it the best explanation in one sentence yet!!