I'd originally bought the Willey X because they were supposed to be so good.  I wasn't that impressed so I bought the Revision Military Hellfly sunglasses.  Ahh, much better.  They fit the bill.  Don't flop in the wind, don't fog up in the rain, are dark enough in the sun without being too dark on a cloudy day or in the rain which means they work great in all situations.  Just what I wanted.