I'm 60/40 on this, in DMX's favor. Even though he's not aging well, he is still crazy ass DMX. I'm also thinking he probably has more brawling experience.
Zimmerman is no good as a striker. That was brought up in the trial by his trainer. But he lost a lot of weight getting in shape in that gym, and he got strong. Although he's gained the weight back, he's still strong, and a known killer. Don't bet the house on DMX. Zimmerman is crazy, and has killed.