I would respectfully disagree. I have used K&N's both drop-in and cone type for many, many years. There is at least one thread on the subject here and several over at titantalk.com. No need to reinvent the wheel, but I can provide some brief specifics. Just for instance, my heavily modded CJ-5 Jeep runs a K&N pancake type filter sitting atop its carburetor. It runs a lot in the dirt, dust and mud. The filter went on the engine almost FIFTEEN YEARS AGO! and has not had to be replaced, nor has the engine been into since it was built at that time. This rig gets really muddy. The engine just keeps on going. Oil pressure, compression etc. remain normal. It does not use oil. That filter flows better when caked with mud and dirt than any paper filter will. Yes, I do clean and oil the filter ever couple years.
My Armada got a K&N drop-in the first month after I purchased it. The Armada replaced a '97 4x4 Expedition I bought new, and which also got a drop-in K&N within about a month of purchase. The Expedition had 107,000 miles on it when I sold it after seven years of daily driving, hunting, fishing, and towing a boat and a farm tractor. Compression was same as new, used no oil, oil pressure normal, never had a problem with that engine either.
BTW, while paper may filter better, there comes a point when better does not translate into longer engine life. The key is regular engine oil changes (3,000 miles - or less if you run in the dirt a lot), and of course, use a high quality filter.
I agree that unless you substantially increase flow on the exhaust side, you are not going to gain any significant power with a change to an oil gauze filter. I use them because I do like to run in the dirt and mud, and because you can buy one and use it forever. With normal use in city and highway driving, you only have to clean and reoil every 50,000 miles.