I wear a brown Giro Encore2 helmet, and although it makes me look like a MiG fighter pilot when i'm wearing them, it also tends to exacerbate the "nose plugging" problem the other reviewer mentioned. If i want to breath out my nose, I have to push the goggles up off my nose and push my helmet up--this makes it so that the goggle is mostly on my forehead, which seems like a lot of wasted space.
Although I have a difficult time breathing out of my nose with these goggles, my vision is unparalleled. Huge spherical lenses = stellar peripheral vision. Their size also seem to help with fogging, too. When they do fog (usually every other time I hit the mountain) it disappears pretty quickly after I start moving down the hill--the vents are large enough to allow air in to kill the fog.
They look great, and you can see great out of them--if i could give them 4.5 stars i would (for the nose-plug issue) but they're fantastic goggles.