I think the biggest benefit is less need or expense to replace the filter. The K&N will work for longer periods than the stock filter between services and servicing is clean and oil rather than replace. The K&N may flow more air before it gathers some dirt but it also may pass more dirt when it is new or newly cleaned. It's a good idea to put some silicone grease on the bottom of the edge seal, especially at the front, to provide a better dust seal.
For those who fear shortened engine life with a K&N, there is a 2003 DL1000 out there with over 400,000 miles using a K&N air filter, Castrol 10W-40 car oil and Fram oil filters, all things so many warn to be bad ideas.
