cai bypass valves,do they work?

im running a cold are intake on my teg and everybody is telling me i better get a bypass valve,i havent ran into any problems as far as rain or puttles but dont wanna take the chance in a locked up motor.any opinions are good opinions for me. if it is worth the money, how about an aem bypass valve,i happen to see one on ebay for pretty cheap.

please search.

http://www.g2ic.com/forums/showthread.php?t=108855&highlight=bypass+valve

http://www.g2ic.com/forums/showthread.php?t=84496&highlight=bypass+valve

http://www.g2ic.com/forums/showthread.php?t=80728&highlight=bypass+valve

http://www.g2ic.com/forums/showthread.php?t=64454&highlight=hydrolock

there have been many threads discussing the bypass valve and hydrolock.