Open Chamber Heads vs Closed Chamber Heads....

Really the thing is the variables are infinite... are both the heads made of the same material cast iron aluminum? Do both the heads have the same exact port shape? Do both of the heads have the same valve size the same gasket depth? Is it on a 318 is it on a stroker is it on a big block.... will these open chamber or closed chamber heads have different characteristics on these different size engines. Were they compared side-by-side on the same day on the same Dyno with the same air pressure?
Maybe someday when some magazine with an infinite budget can make this comparison for somebody on a certain engine it will have validity. Until then it's just an open discussion / argument....