Dynos have proven the best gains have come from two different CAI's. WMS full velocity kit with 95mm MAF, and the JLT CAI. If you have a strut tower brace, you can't use the JLT. The WMS is a pricey piece but I picked up 2mph in the 1/8th and the car definately pulled harder from the butt-dyno. I don't have any before/after dyno sheets, but it did pick up a solid 2mph on the track without changing anything else.
Go with the JLT, you can't beat the price, look, and gains. Tucker put a lot of thought and time into this piece to make it a quality product and it shows. I have nothing but praise for my Ram Air kit. Top notch.