Depends on what kind of power your looking for. Is this for mostly street, or highway use? For the street you cant beat the KB. For the highway I like how my centri pulls. Maybe a procharger?
obviously thats just based on personal preference. Just search and youll find plenty of topics about roots vs centri. Like I said, I like my centri. I think its perfect for a DD and great in the corners cause it gets good traction and has a smooth powerband.