K&N Air Filter Review

So much negative opinion out there on the interweb about these filters. Thought I'd pass on my experiences and findings.
I have never noticed any foreign material on the "clean side" inside walls of any airbox where a K&N was fitted up stream.
I have noticed lots of shite stuck to the "dirty side" of the filter and the catchment area on the airbox. Sand, bugs, leaves, bits of glass etc.
Easy to clean and re-oil. Just ensure you use the genuine cleaning products and follow the directions EXACTLY.
Recharge the filter according to conditions you drive / ride in. More often when really dusty / rainy (water ingress).
I just checked the filters in my cars, all intact, clean on the inside, the outside looks like a woolly blanket with.....

I like 'em, lots hate 'em. Story of my life really. 

My 1250 has a KN filter which was there when I bought the bike.  When I cleaned it out recently I agree with you, there was no dirt or residue on the engine side at all.

the only issue I have ever heard of with KN air filters is on some 4WD's in very heavy dust conditions, but that often comes back to the owners wanting to blow their filter out at the servo half way through a trip such as Cape York.  I use them on my WRX race car, my bike, My 4WD and have never had a problem.

I don't doubt they clean dusty air ok ,it just my 1250 ran better with the original filter . Other bikes I have (or had ) I couldn't tell the difference .
All had after market exhaust .