Has anyone used it long term? It was time to replace my air filter in the xB and paper filter from Autozone is nearly $20. So I looked on Amazon and bought the UPGR8 air filter for $15. By the looks of it - it is an AEM dryflow clone. Quality seems to be top notch as far as fit and finish. After I put it in - no difference is noted, other than slightly quicker rev ups. It was not oiled and in a few thousand of miles I plan to clean it, but not sure what is the best way. It is a dry air filter. Just soap and water? Or what is the best way to clean it? And if anyone used it - how is it holding up long term?