http://www.volantperformance.com/pdetail.asp?ID=90
Take a look at the Volant. I noticed a big difference after the install of the system with there mass air sensor.
The box is sealed so no water or other crap gets into the intake, unlike the Airaid units. The sealed unit also insures cooler air to the intake because it's not drawing from the engine compartment. It's not really sealed just remove the screws on the top when it's time to change or service the filter.
Before I get slammed I'm not putting down the Airaid units. It's just my personal choice to have stayed away from them.