I've put thousands of riding miles in now on the Screws and I have no regrets. Here are a few highlights.
-CHEAP lenses. $20 a lens and they have a lot of options. Solid build quality
-Fit and stick well on my face, don't shake
-Easy and quick lens changes. I don't like feeling like I'm going to break my glasses when changing lenses, and I want it to be fast.
-Thinner arms (which some may find feels "cheap") that to me feels more comfortable than the Radars more rigid arms
-Venting is second to none. Blow hot air directly on the lens and when you begin moving they vent about 3x faster than my radars did
-Cost. Mine were on sale, but with 3 new lenses and the frames, I got them for 2/3 the cost of my radars.
-Lighter. I never noticed the weight of the radars, but after wearing these for a while, I have noticed the light feel they have on my face
-arms. while I like how their thinner design molds more to my face, it makes them feel less "solid" on the arms. You can't have both the mold feel and solid/rigid arms obviously, but I wish you could.
So, if you are looking for great sunglasses that will never fog on you while riding (even in cold/snow/sleet conditions), check out the Spy Screws. They really are awesome glasses.