AEM and Injen Make some really good intakes both short and long. With the short CAI its more prone to take in more of the heat generated from the motor which makes it at times laggy.
The long CAI are good, taking in cooler air, but depending on where its is located could get really dirty espesh on rainy days.

I suggest if your going to get either of them dont have them exposed and have them covered with a some sort of sheild and have an intake tube like a Mugen type intake setup.
I only say this because it makes it legal, wont take in heat generated from the motor and i generally it works better.