It depends on the application but sometimes a pod filter will lead to warmer air being sucked in which will negate any benefit of the freer airflow. Usually a cold air intake (air routed from under the car) will produce the best gain.
2000 Z28 A4
SLP lid, Texas Speed long tubes and true duals
BMR strut tower brace & on-car adj. PHB
UMI subframe connectors, sway bars, LCAs