My experience with these styled hoods in other vehicles indicates to me that performance is probably a wash with either one, so select for style.
About the cowl induction principle:
The base of the windshield is a high pressure air area, so the air gets in as good there as from a front-facing scoop.
On my off-road Explorer, I used a small eBay plastic hood scoop facing backward and pointing to the cowl area, and even with that had noticable change in air flow and throttle responsiveness, even though I was still pushing the air through the factory air box with a True Flow filter.
On my earlier Chevelles, the cowl induction was a worthy addition, and after 7 different cars with various engine setups, I found the cowl hood worth the cost to install for performance sake.
Of course, we know that front-facing scoops work well also. That is a natural expectation from anything facing into the wind.
I sort of like this hood myself... (Vendor price seems high, no recommendation of the vendor!)
Here is another
4.2/6 cylinder engine Ram-air upgrade, Only Fits Goodhoods Non-Returnable
This dyno-proven functional ram air upgrade adds 6 HP and 14 foot pounds of torque or more when used with this Keystone functional ram-air hood. It can also be used with any stock or aftermarket hood but without ram-air effect. Easily installed in place of factory air cleaner box. Only Fits Goodhoods Non-Returnable. [B]Stock #GH-GBXTR