These salopettes were used on my first winter expedition which involved x-country skiing, snowshoeing and ice climbing; snow, gusty winds over 50mph, temperatures from -15F to 35F. They performed well under all these conditions. Midweight or expedition weight bottoms fit snuggly but nicely under these. The close fit is actually good, as baggier would be draftier and any tighter would be depressing. They run rather short on me, but it doesn't really matter as I usually wear gaiters. The length also is not an issue for downhill skiing, as downhill boots have enough calf coverage. They are definitely a worthy investment since the next closest things are Arctyrex and are way more expensive. I bought a size 8. For reference, my pants size is 6-8 in Patagonia, 6 in Arctyrex, S in Prana. I'm 5' 8", ~125-135 lbs, ~33" inseam, ~28" waist.

They fit really well, the thigh pocket is awesome, as is the split-p option. I completely dig them. Note: I did order a 14, when I normally wear a 12. The 12 fit but did not leave me any room for under layers. The Isis rep said they are tailored very closely so that excess fabric is not in your way, so I would advise ordering up a size. But the proportions (waist to hip, rise, body length, etc) are perfect for me. For reference I am 5'6" and weigh 145lb.