I recently was browsing Cabela's and looking at the thermal base layers. I looked at the Cabela's ECWS stuff and was interested in how it appeared, but was put off by the $$$. Since I had some sub zero hiking to do, I bought a pair of tops and bottoms (polar weight). I have used them on a number of trips, both walking (bushwhacking 3-4 hours at a time) and mtn bike riding up and down hills. I tend to sweat a lot and my truck gets very wet.
First observation, my legs never felt cool, let alone cold, and the fit was perfect. I love the fact that these are a quilted design which I think really helps with the warm factor. These will be my go to bottoms when it is below freezing.
The tops: I am not a big fan of tight fitting, so I might get a size larger next time. That said, having thick cloth over my belly, thin under arms and down sides, seems to make these very efficient. I am really impressed. I will buy more.
Conclusion: other than cost, I really like these. I think they have a winning technology that will go a long ways...now if only the price would come down some ;-) Anyone else have any experience with these?