yes, they, are very warm, very, very warm. I use them steelhead fishing, standing in 33 degree water for extended periods of time. Outside of that the are too warm
Jeremy - go with LL Bean ... they make excellent waders and have a great warranty policy that you will not get with Simms ... I am pretty sure that you can get equally as high quality waders from LL Bean as you can get from Simms. Simms makes awesome stuff, highest quality, but again, you should be able to find equally as good quality from Bean.
"It was the blackest night! There was no moon in sight! (You know the stars ain't shinnin cause the sky's too tight) "