I havent personally used it yet, but i've been doing some research and its mostly positive. I may be ordering my kit in the next month or two.
The only real caveats are:
1. some people have some issues with getting the cold-start tuning. Supposedly it was some issue relating to the v2.1 software. I'm not sure if that was solved.
2. The included fuel pump is loud/cheap
Other complaints are the typical political "from china" bullcrap arguments. The parts are built in china, but the designs are american(formerly retrotek). And the quality is quite good from everything i've read.
I've got two professional products parts on my 5.9 magnum duster(balance/intake) and i'm very pleased with the fit/finish of them.
