Best HEADER?

Ok i have read some threads on headers here and i am still confused as to who has the best header!

WTF is Chikara?
are Greddy's headers any good? will it be good with my THermal classic that is on the way?
IS DC sports better? and worth the Extra $100?

i know APC and the likes are SH*T so i dont even mention those, but i am really curious as to who has the best header, and how much MORE gains i will see over my Thermal Classic that gains
7-9%, along with FOCUZ high Flow CAT, and AEM CAI?