Timthetoolman

Being a long time dirt biker, including in sandy desert, I have seen many bikers run the K&N to get a little better air flow and performance. I personally did not run K&N but had nothing against the product.

It is very common to see posts like this: What is better in the sand? Foam filter or K&N ? - ATVConnection.com ATV Enthusiast Community see post #3.

which indicate more silica in the oil.

Your experience does not match up with these. Unless the oil was also tested after using paper filters and the data compared it may not be possible to say if one allows more particles into the engine than the other.

The bottom line for you is that it does not matter since the silica readings are clearly not a issue.

Timthetoolman

Here is another post: Threw away K&N's due to high silicon in UOA's | Engine Air Filters | Bob Is The Oil Guy

I am still not against using the K&N air filter but I would do a lot of investigating and run UOA to be safe.