Kinda seems like you are stating the obvious here. More airflow means more risk of contamination but how much more. How much more risk do the K&N filters pose to your vehicles engine than the paper air filters. I think the real question is "Is the risk worth the reward"? At least that what i want to know and the only way to decide that is to have actual scientific research and tests performed on such products. Hmm after checking the internet (google) it just so happens that such a test has been perform
http://www.bobistheoilguy.com/airfilter/airtest1.htm
Thump is your name bob? Even though you say this post is not yours it is almost word for word to the above link, right down to the educational backround.
Just checking