I've just ordered my second pair of these to replace my original well-worn ones (of at least three years service!) They are extremely comfortable and close fitting and really do make a huge difference to the warmth of your hands when worn under your usual gloves. Personally I twin them with a pair of fingerless skiing-type gloves and, due to the sheerness of the silk, this still affords maximum sensitivity to handle/feel delicate things making them excellent when out fishing for example. Highly recommended.
[Edit: 18/01/10] I have been wearing my new pair for a week or so now and have found them to be slightly thicker (and therefore less sheer) than my previous pair. Consequently they lose out on a bit of touch sensitivity. On the plus side though they are even warmer. Still well worth the money I believe.