I have a pair of those omni-reflective gloves - they work really quite well for any kind of outdoor exercise in the winter (cycling, hiking, etc.). If you're body is sweaty and warm they warm up quick and stay fairly dry.
The problem with any gloves, even these, is that they separate your fingers and increase surface area, making it a lot easier to lose heat. Mittens are the solution to that, but the problem with mittens is that you lose dexterity and look stupid.