I started wearing the CW-X tights under my ski pants last year. I tele ski, so it's really quad intensive. For me, there was a noticable difference in fatigue level; I was able to ski longer (each day) than I had been able to without the tights.

Now this may be because (1) I knew I had them on and therefore believed they were doing something, (2) I was just getting in better shape, or (3) they actually did something. I don't know the real answer. I do like the way they feel though; they are very supportive and for quad-dominant folks like me (another way of saying "thunder thighs" ), that's a plus. It won't hurt to try a pair if you have the $. They are very well made and I would certainly buy another pair.

I just got some of the CW-X shorts from Sierra Trading Post but it's been too cold to wear them running. I have everything from Target Boutique knickers to the Hind Peak to Peak pant. Usually I get too warm in the Peak to Peak and just wear the standard Adidas running pant (not a tight) or the Brooks dryline tights. For me, the thinner the better; my main concern is having my knees covered.