Yeah, the COD needs more gain to really start to sing in my expereince. I totally agree that the TD B or BMan hit with esoteric gain box of your choice will be the best bet.
It's been my best find in tone yet. When I first got the Zen Drive I was a little mystified. I could not dial it in. Wrong guitar (PRS CE24) wrong pickups (TomA H2+) and wrong module (SL). I put it away. I got it out again after I put a Suhr pickup in my Les Paul. Then I was messing with my B'man module it there it was, the sound evrybody raves about. I didn't get it until then. John is right there are a number of OD pedals that will do, MI Audio Blues Deluxe comes to mind too, but man the Zen smokes with this set up.