Oil bath air filter is FAR FAR superior in dusty climates.
Also K&N is well noted to be extremely poor filter "at first" by offroaders. Once it is dirty then it filters better than many aftermarket filters (but not better than oil bath) .... it uses the collected dust stuck to the surface of oil sprayed on the the filter as part of the filtration. Problem is then you never really know when to clean it..... Except knowing not to clean it when you will be getting into a dusty environment soon.
Coach,
having had an oil bath filter on my ol ford - it did work well, problems that arise is viscosity of oil used and volume of oil used - two variables that if not in "spec" would be very bad news for your engine!!! And if allowed to sit a while unchanged, man there is a mess in the bottom of the can ! BTDT
also - studies have been performed over the years that "paper" filters - filter the air better......but that too is a little misleading, the VOLUME of air that a high performance engine sucks in can flow through a "paper" element "better"
the oil baths are still used in reallly dirty/sandy areas of the planet!
here is a good reading on the differences and why each is better than the other:
https://en.wikipedia.org/wiki/Air_filter
I think the bottom line is that too many people could not, or would not change the oil - it was too messy ......so the "paper" ones came out and made it mo' betta and simple for the average owner!