Sturdy and warm. I just got a pair of these boots this fall for the winter. I was tired of my feet being cold in another pair of boots that are for 3 season use and decided to invest in a pair for Ice climbing and winter mountaineering. I found the Nepals to be pretty warm. Although if you are standing around for a while, your feet will start to get cold, but I think that is true for almost all boots. They are stiff and I like it. When I was climbing ice in them and was having a hell of a time getting a screw out, they supported even though the calves started burning like hell, it was not as bad as some other boots I have used. I think they are a little on the heavy side, but it isn't like I get done climbing and feel like I have bricks on my feet. Besides, what does it really matter once you put some crampons on your feet how many ounces your boots are? I also like the funky colors. This pair of boots will be my 3rd pair of LaSportiva's and none of them have ever let me down.
Board lasted, 3.2 mm silicone inpregnated idro-perwanger roughout leather with high abrasion resistant fabric, Vibram rubber rands, gore-tex insulated comfort lining, insulating Ibi-thermo insole, 8-9 mm TPU/ PU inserts with Aircushion, Vibram outsole with impact brake system.