The proper manner in which to ask this question is how restrictive will a filter be at a certain CFM as technically, a filter can flow almost any CFM as long as it does not collapse.
More surface area is better
When selecting a filter, the more surface area you have the better it will perform. You ultimately want the largest filter you can fit properly in the area as this will yield you the best results including the lowest restriction level ("H2O). Be sure to leave adequate space around the filter.