Not running one personally but have installed and tuned a handful , do you have a specific question ?
powerdynes kit was not out all that long although I don't think it was because of any specific problems. I found a vortech V3 for a nice price and polished and installed it.
I am running the power pipe and I actually made the pipe between the vortech and the upper with the bypass valve on it. I think it was a 3.5" pipe with a 30 degree bend to start with that I cut to fit and then had someone weld the bypass valve to it.