Fantastic. warm and light - Western Mountaineering Flight Pants - Mens

These are typical WM quality. The fabric is called Microlite XP. It reminds me of the fabric on the MH Ghost Whisperer.
It is ripstop, but so lite it's hard to believe. Ditto for the Gore Windstopper fabric on the knees to cuffs) on front and seat.
Don't think of normal Windstopper- this is tough but super light weight. The zippers are a perfect size and weight and made by IDEAL, not YKK as the WM website indicates. I'm 6'4 and 200 lbs. the XL works great, with 34" leg length. Lots of down, but not too much to look like clown pants. The waist and cuffs are elasticized and work great. A very light belt helps to snug them up tight.
Used at 0 degrees and -25 wind chill inside a 0 degree WM sleeping bag. Toasty wearing a stretch fleece tight underneath.
If you are in the market for down pants, these are an excellent choice. Note there are no pockets.

This review was written in the old system and had content requirements that are different than reviews written today.