I bought an LBZ mouthpiece for my truck cause its way better than the stocker plus its cheaper than the AFE piece, I read somewhere that the Kodiak piece is smaller than the LBZ but not by much.
For the price id definatly do the LBZ its way cheaper than the AFE and its the same size, only "cutting" i had to do was grind down the flashing on the bottom side of the piece and it fit fine(once you test fit it you will see what part needs to be taken out and its not that much).
As far as the benifits i definatly noticed the boost came on quicker(i dont have a guage but i can attest it definatly came on quicker) and the truck felt peppier a good deal.
Only other thing is you will need to cut your stock intake to fit it to the mouthpiece OR just pick up a used stock LBZ unit or aftermarket LBZ unit and it fits fine. I browsed the classafieds on a couple forums and ended up picking up a used already cut to fit AFE Stg. 2 for 75 bucks that had 2 filters that came with it and a pre filter.