Never really noticed much difference in sound from my cai; as I had the upgraded Z1 with the race version filters & large bases.
Pending on what your goals are & having the 7A/T, might want to consider a new diff & gear swap
Going from the 3.357 to the 3.692 makes a pretty big difference on the bottom end & midrange
Also allows you to get a true positive traction unit, like a Wavetrac helical or something of your choice.