Still running stock, I figure I'll swap the filter when I get my pipe and controller. I always liked K&N, but I think I'm gonna run a Uni or Twin Air this time. All the research I have done has shown foam filters to be better for dusty conditions.
Well its just that I am a Real technician and have seen the results of a K&N filter. Just prefer the foam/oil. Check your oil next time you ride in the dust just after changing it. It will have allot of dirt from the air your bike is breathing. Try it some time thats all. The only reason oil gets dirty is because of the air intake.
Like I said, if you ride a lot in dusty conditions, foam is the way to go. Uni has a filter available now, the part number is #NU-4143ST. Since I have yet to clean my stock one, I dont know if you'll need a filter for the breather as well if you swap out the stocker, but I would think so.