Here's my 2€ents worth. I spent 40 years in the filter industry with a company that makes 85% of the air intake systems for Diesel engines in North America.
As a corporation, we had a look at the K&N type technology and spent a lot of R&D dollars on it. We were unable to get the efficiencies we wanted so the program was scrapped . Air filtration is all about maximum cleanliness of air going to the turbo with (efficiency) with the lowest initial restriction when the filter is new and clean. IMHO K&N will slightly reduce your restriction but will not give you the cleanliness efficiency your engine wants. If your running all pavement, minimum fine dust...probably OK. For my $ I stay with the OE system that has had hundreds of thousands of dollars in research spent on it.
Floyd & Carolyn
2012 F150 S/crew 4X4 6.2L 6Spd Tow Max Firestone airbags.
2011 28RKS Wildcat. Yamaha 3000iseb Generator.
2013 22 nights.2014 57 nights.2015 116 nights +14300KM
2016. 96 nights