I guess what you need to determine is how those people determine what is better. If the goal is to flow as much air as possible, and the air flowed by the Amsoil is better then the K&N, then it is better. If you focus is on amount of particles that get through, then maybe its not your best choice. I mean really, we are splitting hairs here. I will take air flow way over particles. The only thing you need to worry about is the big stuff that can damage components. All that dirt will burn, or get expelled, in the process anyway. Now if that stuff was passing through your injectors, that would be a different story