Lab tests may not be accurate concerning the K&N. The point being is that a vibrating engine rattles the filter oil vapor trapping dirt.

The best test is a self test. Wipe the inside of the filter housing to monitor it. My K&N keep dirt out.

that said
re-oil 7.5-10k miles
I use wheel bearing grease to seal filter to the housing.

Jim Conforti knows his stuff. I'd listen to what he says

Listen to what he says or does? Alledgely he says oiled filters suck. Yet his cold air intake uses one? Hmmm Lets see. F1 teams use BMC filters becuase they (sarcasim) dont filter properly and are no better than paper? I dont think so. After sepdning 200 million a year they are going to use what gives them the best performance and reliability. Nuf said

paper filters are good when new. Cotton fabric oiled like K&N and BMC have to be in the same league?

Real world test: I've been running a MAF with K&N filter for over 10 years and over 100,000 miles. The engine was rebuilt this summer ( big time oil leaks and a broken head stud) and found no wear inside other than a little on some of the main bearings. The hot wire has never been replaced on the MAF. Its not on there for hp. It came with the MAF. If I was running the stock air flow box I'd probably stick with the stock filter but only because it would be stock. I do not think they add a thing to the hp of the car. They do sound kinda cool though.