I currently have 2 Phaze II's and a DDT coming, so this isn't official as a side by side comparison yet. But based on cores I expect to see the DDT to be a bit more rounded/even than a Phaze II with the same drill. DDT core will roll earlier but not as strong a diff, PII naturally clears the fronts a bit easier and the motor corners more strongly.
I am planning on my DDT to get me in play at Nationals on the team fresh. I don't think either of my Phaze II's are quite what I would need on a high friction condition the way they are drilled, they are pretty strong off the spot. I did use the pin down P II at USBC Masters quite a bit after the first transition from fresh, pin up was too sudden off the spot. I do adjust covers quite a bit and use that adjustment to create separation between my shells when I want a couple options that are similar, but not the same.