On big builds cars there is limited space for the huge filter to sit in the inner wing hence why you tend to see induction kits being used.
AF prefers cai and is proven with his mapping.
I've ran both cai and ik with no issues when mapped correctly.
It's purely what you fancy. 10 horses here or there won't make a huge difference on the road and won't suddenly make you a 1/4 mile hero.