The gloves work fine. As for cold, we have not had any except yesterday and today (it's about minus 10 right now, brrrr).
I find the gloves work better on the PlayBook than the BB - the screen on the PB is bigger and more "geared" to touch than the BB and I often just use the touchpad on the BB and click the mouse and type via the keyboard. But when I use the gloves on the BB touchpad and on the screen to select something, they work fine.
The figers on the gloves are not all touch-enabled, only the thumb and forefinger can work the screens. However, I noticed on the PB that the glove "touch" and click selection worked better than the capacitive stylus that I normally use (however, this thing is about a year old, so it might be wearing out, if that is possible).
I use the gloves outside a bit, in the car for instance (when I am parked!!) but not out in the cold walking around - I just don't get the BB or PB out in that situation too much - for example, I would never use the BB on a chairlift, as I would hate to drop it, and with my luck it would splash down in an open creek!
Bottom line, I would say the gloves are neat and they work well but for me their use is limited - the best application for them for me is in the car or subway, just doing emails etc on the BB when it is very cold - we just have not had any real cold times yet.