This would be the only reason to get it:
Ain't it purdy?!?
But in all seriousness, I do drive on back country roads, a lot of dusty gravel ones, go mudding a little, etc. I haven't had a problem yet and I've had it on since spring.
There have been people that complain about dirty although I haven't had any problems as of yet. They do make a prefilter that will slip over then end of the filter which will trap even more dirt. You may want to think about that "upgrade" to the k&n.
All in all it was basically a mod done for looks. I can't really hear the sound over my glasspack, although I heard it sounds nice (LOL). Gl!