anyone running an aftermarket airbox with just a screen cover? any issues when riding through mud or water?

i am thinking at least of replacing the airbox cover with a K&N filter cover and replacing the stock air filter with a K&N filter with sock..

option 2 is replacing the airbox with a UM metal box with a mesh cover and replacing the stock filter with a K&N filter with sock

i have 2 kfx 400's 2006 but i want to try all the mods on one before i do the other...