I used Ram Flo filters on my Bagheera (I still have them somewhere) and I was not impressed. They look cool but not a patch on K & Ns etc in terms of airflow.
I wouldn't buy them again.
Well..... they are bought and payed for now, so i guess we will just ahve to see how they preform on my dellorthos...
Anyway.. they are cheap, and i have never expected an airfilter to provide anything but a little extra noise.
My main reason for buying bolt on's was to get rid of the homemade airbox in my car.. that thing HAS to be more restrictive to airflow then even "bad" bolt on filters.!