Hmm.....your comments have me a bit confused on this subject.
I've used K&N's in three of my previous cars with various results.
In the 4cyl VW engine I noticed a major change in throttle response as well as a 2-3mpg increase in gas mileage.
In the 6cyl Honda I didn't notice that much of a difference in throttle response however gas mileage did increase 1-2mpg.
Now what I've heard in regards to filtration is that the K&N's are better than a paper filter. They supposedly trap more dirt and will do this over a longer period of time (30 - 40K miles).
I'd really be interested in hearing test results that prove or disprove this, other than what's on the K&N website.
02 C32 AMG
84 190E 2.3 5 Spd