Leftmost image is my front intake with Corsair stock filter with Demciflex aftermarket filter to keep the dust out of my system.
Since i have high medical grade mesh filter in use, the regular AF fan with low SP value wouldn't have enough power to pull enough air through restrictions (filters). That's why i use Corsair ML140 fans there. Corsair ML140 fans have high SP value to pull enough air through filters while still having high AF value to move a lot of air.
Middle image is the case with stock Corsair grille and filter. My case arrived with it.
With stock filter (which isn't that good), the AF fan might do the job but since there are restrictions in air flow, the SP fan might be better to use.
Rightmost image is without stock grille and filter.
Without any restrictions to the air flow, the AF fan would be best to use. In this setup, there's no need to use SP fan.