That's just not true, just because it was on the internet doesn't make it true.
K&N filters filter just fine and filter better as they get dirty.
Whatever you read was probably planted by someone backed by a paper filter maker.
Your probably right there, but you can't take what KN says as gospel either. After all they are trying to sell a product here.
My only expirence is with my 72 Buick Skylark, a 455 with a carb. I read the KN advertising which told me my car would be just as fast with their filter and air cleaner than running without one at all. So I bought the 14X4 filter and air cleaner. All said and done it cost me a hundred and thirty dollars and .4 ET in a quarter mile. I'd vote for a good brand paper filter if I was buying.