Tried it on as soon as it came in the mail and it fit nicely. Then I washed it... I'm 6'7" and I am used to having to wash my clothes a certain way to minimize shrinkage. I washed this in cold water and air dried it like I do all my clothes. And what was once a nice fit length wise soon became way too short in the crotch region. I have a semi-wedgie when ever I wear these now. Other than that, these are well made and certainly warm. They probably fit average sized people really nicely.
Ordered a large but a medium might have been the ticket. I'm 5'8" w/ 44" chest. Reason: The crotch is halfway to my knees causing inner thigh chaffing. It feels like I'm wearing a diaper when wearing under pants.The material is excellent, however, the button holes are already fraying. This can be fixed with a needle and thread. The rear fly is anatomically correct and won't cause any mishaps. Works great as PJ's.
I live in MN and wear a union suit all the time. I have always bought a Duofold, but they no longer make them in grey and I do not like red. Unfortunately these ones have a terrible fit - very dumpy in the mid-section/crotch. I am 5'7" and ordered a small. I would have to weigh 250 lbs with a big butt to fit in to these. I like the fabric, so I will rate it a two. Back to the red DF for me.