In reply to blue_sundown:
I agree, I have a mountain hardwear jacket made from the stuff and it's a bit rubbish TBH. The material isn't very warm and the seams are so leaky that even the slightest shower results in wet shoulders and because the material is quite stiff it doesn't sit so naturally and wind blows through all the openings. My ancient Rab cioch (I think) softshell jacket made of powershield is warmer, more comfortable, equally wind proof and more waterproof.
The only point that the windstopper material wins on is that it's lighter.
As an aside, we had a good chuckle while at the works a while back when we noticed the climber next to us was wearing tights with the windstopper logo on belt line just above her bum crack. Not the back product placement we thought.