It had not been above freezing where I live in over a month.  We were literally frozen in negative and single digits with windchills that drove temps down to the negative 20-40 range.  I needed something better as my gear was just wore out.  I took the jump up to buy these Arctic lined Carhartt's and couldn't be happier.  In order to give the suit a real test I broke all the cold safety rules knowing I was 25 yards from the living room couch.  I went out in a light cotton shirt, jeans and a base layer of whitey tighties.  Outside temp was true temp of -15 windchill -30-40.  I had to clear snow with a snowblower and was out side 2.5 hours and was toasty warm.  The only places that got cold were my fingers and ears - obviously not the fault of this suit.
I am a big guy 6ft and 330lbs.  I bought based on the measurements guide and even then the suit is a tad large in the mid-section.  I am glad I ordered the size I did as I found it handy to have the room to wiggle when I was laid out under a truck hooking up a tow strap.  So far zero complaints and I don't expect there to be any complaints.  Another great Carhartt purchase I love.
Comes in a huge box that gave the kids weeks of enjoyment.
If I had to repeat the purchase I would.