For the 1k mark you are pretty much getting the same performance no matter what you buy. BC/K-Sport/D2/XYZ/YellowSpeed from what I've heard (obviously speculation) they all come out of the same factory in Asia. None of them are independently dyno proven to be good at what they do. Meaning the 50 million adjustability settings don't mean a lot. Again speculation but there really isn't alot of info out there to prove otherwise.