Anyone have any experience with these. My girlfriend is due for an air filter change very soon and I was thinking I may put in a cotton Gauze filter such as a K&N rather than another paper filter. K&N are pretty expensive and the Kool Blues seem to be a much better deal. But I'd like to know if flow okay and especially how the construction is. I for sure know a K&N will last years and years but I'd like to know if the Kool Blues are the same. Thanks in advance.