The only problem I've ever heard with Harley filters is someone either overtightened it, or left it loose. As far as filtering, I haven't heard of anyone having problem with them. I get them for about $7 piece and after I use them, I throw them away.So paying alot of money for something your gonna throw away, doesn't make sense to me. If the K&N is working for you, keep using them it makes life simple.,,