I agree with Rickbin's post. GT makes a great membrane but they can't fully control how it's made into clothing. If it's not done right, it will leak.
One problem I've run into isn't a problem with the GT. They make boots with the GT booty on the inside and insulation outside. If you're in cold wet conditions, the insulation will get soaked while your feet are dry. It's like standing in a bucket of ice water with your feet in plastic bags.
