I have never used a K&N before they are about $48 on EBay
Actually its a great quality filter that's suppose to be reusable. Its costly because of the quality and re-usability feature but has to be cleaned and re-oiled from what I understand.
Increased air flow and increased mpg/power are suppose to be the benefits.
In my opinion: The mpg is a misnomer as its hard to document. The increased air flow is another misnomer as these modern vehicles can and will maximize mpg at OEM filter air flow.
Air to gas flow is regulated automatically.
The engine's gas/air will also automatically adjust as the filter's air flow decreases with age and that can lead to a loss in mpg and or power at some point if it gets dirty enough.
Actually all filters have a micron filtering limit, which will prevent larger dust particles etc. from getting into the engine. A poor filter that allows larger particles through can be bad for the engine.
That is why you must be careful on the quality of the filter. Brand name filters are not generally a problem.
My personal opinion is I would rather replace the filter at 1/2 or 1/3 the cost of a K&N with an OEM standard one or one that guarantees the OEM standard.
Filters are fast and easy to replace with a clean one.
I tend to still replace my air filters 12-15,000 miles though I could go longer per the manual.
PS I did order the combo, as at a minimum the cabin air filter in it is less than an OEM one alone.
I generally have not had issues with stuff from China. I have gotten all my power lawn equipment filters etc. there off e-bay.
They have always been spot on in the description.