Katdiesel---guess thats My liittle trick.
When you call up to purchase the TM, you really have to know how to talk to the sales people and hope that you get the right person to talk to. When I was trying to purchase one, about 99% of the people that I talked to wanted to tack on a Core Charge, kind of insuring that they get your stock ECM back, or they charged you a flat price that included install (again so that Cummins can get your stock ECM returned to them). Fortunately, the last time that I called I talked to this guy that seemed pretty new. he didn't want my VIN number nor type of transmission. So I figured that I better buy it while I can.
As JNutter said, I do have the TM running with the DD2's and it has seemed to help me retain my bottom end for towing in high altitude. I guess the question that comes up is "Is the TM worth the cost?" Well that totally depends on what you are doing and probably altitude. As JNutter said, the TM actually changes the Fueling curve, it doesn't just give you power. Being that him and I are both located in high alititude, our trucks are lacking much more power compared to someone at sea level. Yes the TM rediscovered a lot of power, but it seems to give me power in a broader RPM range then stock.
I hope this helps.
Please feel free to e-mail me if I can answer any direct questions.
Thanks
Kev