Evosport at the time did not have a dampened crank pulley like the stock one and Renntech did.
Evosport had mixed reviews about the pulley issue on most of the MB forums I was searching on.
Renntech had no unhappy customers that I could find on those same forums.
Evosports package with the ECU program is $2,850 if I remember right, without a dampened crank pulley...
now I see they have a dampened pulley upgrade for $999. Or just a pulley kit for $1,999 without the ECU program.

The Renntech kit is only $3,000 for the Crossfire SRT-6 and it comes with a dampened crank pulley along with the other pulleys and ECU program.
So that's why I just chose Renntech.