You won't notice them...
- Familiarity: I've used it several times
And I'm pretty sure that's the point!
I've been on the mountain with these since the start of the season and they have me really impressed. The red-tinted lens does a very good job of enhancing contrast, and if you never look through a Prizm or Chromapop lens you won't have a complaint. It's just not quite on the same leve that you get from Smith or Oakley. However, what these lack (only marginally) in contrast-boosting dyes they more than make up for with the VLT-adjusting tech. Last time out I got all 4 seasons in a few hours and the photochromic lens was as advertised. I didn't really notice it change tint as the sky went from heavily overcast and snowy to almost bluebird sunny, but I also never felt like I had the wrong lens on. Meanwhile, my buddy swapped out the lenses on his Smiths at least twice over the course of the day.
As for comfort, the frame and foam feel fine. Oakley is in another league with their foam in my opinion, but the Cyrius's flexible frame should help these fit a wide variety of faces and the foam is more than comfortable enough for a full day on the mountain.
The one thing I haven't been able to do in these is night riding but based on my experience in low light so far, I'd bet you could get away with it.
Basically these goggles work well enough to make you forget you're wearing them.