John summed that up well. 
Even with a forward scoop, without proper channeling of the air once it enters at speed, it does you no good.It's just cooler (than engine bay) air that is being forced in and then heated up with the rest of the air, with no use.
What you need is to get that forced in air to the intake (whatever option you use - CAI, airbox, etc). Getting the air there before it is warmed is ideal.
A forward scoop with a hole in the hood has 2 uses a few uses:
- lets cooler, fresher air in at speed.... but this new air is basically useless to you (must be captured and directed to the right area)
- well, it looks kinda neat, right? 
- lets rodents have an access route for finding warm places in the winter 
What I find ideal is, getting the air to where it is most useful and ALSO being able to pull the warm air from the engine bay in general. I am unsure that we get enough flow over the hood at speed to have a fruitful "draw" of air to be pulled from some sort of insert extraction. This is the mud hole I sit in now. I am considering pulling off the OEM skid plating below the engine bay to promote more flow, but it may not be enough to even bother with. Then, looking at cowl options, whether they be insert related or actual hood modifications.
God! Dont you just love projects?!
Gary Noonan
'01 S/C VX / '18 Forester XT