Be sure to size up on these guys. According to the Icebreaker sizing guide, I should be a small (5"6" , 130 lbs, 32-26-36). I was able to get these leggings up just past my knees, and thats it - the legs were tight, and the waistband was sooo tiny. They are not stretchy, though the fibers probably loosen up with a bit of wear if you can get them on. Can't comment on anything more than the fit, since I wasn't able to get them on, and had to return for a Medium.
"Get the right size and you'll be happy for days on end."
Wore these for 4 solid days on the trail, took them off for a day when it warmed up, then put them right back on for another 2 days. The waistband looked tiny & the legs felt a big snug at first, so I wondered about freedom of movement (size Medium: 5'8", 145bs, 29" waist with large, athletic thighs & butt) - after donning on I didn't notice them at all while carrying a 30lb pack over the rocky, rooty climbs and descents of a fairly rugged trail. They're warm enough on windless mornings above the freezing mark at camp to make a pot of coffee and get breakfast on, don't hold odours or moisture if you stick them in an outside pocket of your pack to air out a bit, and feel delightfully soft against your skin. Wouldn't head to the backcountry without these (or a heavier, warmer pair for late/early season) in my pack or on me. They do run a tad small compared to other Icebreaker bottoms, but the snug fit let them sit comfortably under my hiking pants and the gusset lets you move freely.