I am 5'8" and 150 lbs and the medium fits particularly well. It is not a fitted piece but it is not overly loose either.
Pros
Excellent lightweight thermal polar fabric.
Good fit.
Lots of details (generous zip slash pockets and arm shoulder pocket), adjustments for hoody and hips, and fingerless glove.
Seems very well built.
Cons
Needs a wind break layer.
Arm zipper is tough to open.
Overall an excellent addition to my outdoor wardrobe. Highly recommended.
This review was written in the old system and had content requirements that are different than reviews written today.