Well it's 42 degrees out and I put some of my summer thin leather gloves on for the test. My fingers are compleatly out of the wind. That doesn't make them automatically toasty warm, but if you have a warm glove on the wind won't be a problem. I just fee a little wind on the top of my hands.
I got them from the NC web site so they weren't cheap. I would recommend these if you don't want dirtbike guards. They look good and are functional.
True they arn't very manly, but if I had to choose between style and function, in this weather I choose function hands down. They will come off when it warms up again. The windscreen too. There lies one of the biggest advantages. I can take them off in a few seconds now that my mirrors are broke loose.