[MFury]

If your talking about the water prefilter stocking they send or offer as an option, it would cause more air restriction but splashes onto the filter would run off instead of soaking in. Maybe wrap it for the wet seasons if you see alot of deep puddles in your driving area? I don't think it would prevent sucking in alot of water if you totally submerge the filter though.
Haven't seen any dyno to show just how much it decreases your CAI gain.