It pumps air better. I'm not versed enough to know exactly how that'll effect your dp. I'm not sure if that means it'll flow even more air to turbine creating even more dp or if that means it'll let it breathe better resulting in lower dp. If forced to guess, I'm thinking it'll be worse. PURE speculation on my part.
What rpm were you running it at on your cummins? For a given rpm, them increased ci & airflow are going to be different on the Dmax.
I'm curious to see how the holset does because you just don't see many on a Dmax & I've often wondered why?!?