I use mine for mountain and road cycling and love these shades!! I have a medium sized faced and I have found these shades to stick on my face without sliding off. The frames do feel a little cheap in your hand, but they seem to work just fine. I have now used all three lenses for sunny and cloudy days as well as night riding and all works perfectly. All in all no complaints.
03/29/2013 Update: I've had mine now for a few months now and the left red mirror lens has been scratched probably by a hanging branch. I just got off the phone with Smith Optics customer service and they don't warranty their lenses. They sell their lenses on their site for $40 a set only and I was told I was welcome to buy the whole set (even though only one lens is damaged). They also have a recycling program where you can send your glasses in and get up to 50% off a new pair. I've never worn a pair of sunglasses before while mountain biking that became scratched so quickly and easily. Either way, I'm done giving my money to a company that uses sub-par materials in their craftsmanship and does not back up their products.