Oil does have more flow but I do not like to damage my MAF sensor. Some dry filters are washable and no still produce plenty of air flow.

Performance is determined by two things: flow and temperature. More filter surface area = less pressure drop = more flow. Lower temperature air = more dense air = more oxygen flowing per cfm. The volume past the filter acts as a buffer, improving throttle response. That's most of what you need to know when looking for or designing an intake.

at the stock power levels, I would say its mostly true... Hell i would even rip the stock airbox and throw on a 3" K&N filter for shits and giggles.. There is something to be said about a properly designed intake (like Airaid or SRT) specifically for your car though...