I had a CAI on all of my cars. The EP3 sucked up water...only a little bit and stalled...but started right back up.
Then with the FA5, I came close to sucking up water when it rained a ton in San Antonio. So I had enough and just made my own "Icebox"...basically used the stock intake and redid the rest of the intake tubes to capture air below. I had more hp with that than with other FA5's running SRI when I went to a dyno day.
So in the end, from my experience...I'll be sticking with a custom intake utilizing the stock intake box.