I would and do recommend SF filters to my friends. K&N has a production facility in my hometown and I'd rather import an SF from Italy any day. The SF I have is the standard filter, not the waterproof version.

Most of the guys here in the US will recommend stock air filters over K&N just due to the amount junk K&N filters let into the engine. SF is one of the few that are recommended if you don't use a stock filter. Like I said, I've used them in the past and refuse to put K&N filters into any vehicle I own now or in the future.