Fogging is the big issue for me. No downhill for me; it's all backcountry XC or snowshoe, sometimes way back there and alone, often hot and sweaty work. I just had a pair of Bolles (gift) fail during a typical Pacific NW storm today - my own private whiteout. These Smiths are pretty much advertised as the solution to my problem. I'm also looking at the Anon Hawkeyes and the Oakley Crowbars. Obviously I will have to try them on for fit but what does anybody have to say about ventilation? Side issue: peripheral vision.

Nobody likes a whiteout that exists within their own goggles. Smith goggles, including the Phenoms, do have a great venting system that lets hot air escape easily, which works especially well when you’re downhill skiing/riding, and your gogs are getting plenty of cool, refreshing airflow. But if you really want to amp up your ventilation during sweat-inducing aerobic activity, you should look into the Smith Phenom Turbo Fan Goggle. It has a tiny, quiet, battery-operated fan inside the goggle, and paired with Smith’s standard anti-fog lens, this fan keeps things super-fresh and clear even when you’re hot and sweaty. (You turn the fan on with a simple switch on the goggle’s elastic band.) You’re pretty much guaranteed to not have a fogging problem, and if you’re worried about the fan breaking down at all, remember that Smith (and Backcountry) will back it up with a lifetime warranty.

I've had terrible problems with fogging ever since I started snowboarding, and so far these have been all but fog proof, and I've definitely put them to the test. they're the best I've seen, and In the past I've gone through top models from Oakley, Dragon, Von Zipper, and Electric (I love goggles a little too much). While the laws of physics might prevent you from being able to see during really sweaty activities, these will likely serve you quite well under normal circumstances, especially if you don't wear a helmet