There are those that love them and those that have never considered putting one on their airhead.
I am in the second group.
There are two other screens between your fuel supply and the carbs. Those should be checked once a year for contamination.
If you empty your tank, and remove your petcock, you will hopefully find a clean screen with no liner peeling off onto it.
Some folks report finding no filter in there. NOT a good thing!
RealOEM linkThe second OEM filter is located at the bottom of the petcock, just above where the hose pushes on.
Duane Ausherman has a good section on measuring fuel flow on his site:
http://w6rec.com/duane/bmw/petcock/index.htm (scroll down)
(remember, Duane is pre-R65...)
"An Everbest will flow 100 cc of fuel in about 12-15 seconds with a half full tank. Only when it would get up to around 20 seconds would I remove the petcock to investigate it further. A full tank will flow more fuel than a low one, so take that into account in your flow measurements"