Wore these over my Grippi Lining Glove, whilst going Halfway up Snowdon in 55mph winds and -2c.....I put these on a quarter of the way up the walk, and my hands were very warm indeed. I couldn't feel any cold air whatsoever. I bought a medium using the sizing chart, but over a lining glove (I don't use lining gloves all the time) they could be a size L (although the sizing for the Lining glove was different as I bought a size L accordig the the chart for these)
Overall in modest windy cold weather, they are great on their own and superb with a lining glove (see above)....but yet to try them in the rain. I had to remove all gloves to take a few quick photos and my hands soon became raw - but once I put the liner glove and these back on - the difference was amazing!