I agree with you that manifolds are a big power loser.
I'm saying that FW headers are maybe, maybe a bit better than manifolds. Maybe. They are way too long and usually the primaries are way too small along with small collectors.
If I had two choices between FW headers and manifolds, I'd pick the manifolds every day of the week, and get a cam ground to do as much as you can with the manifolds.
That's what I'm saying.