I am 6'2" 230lbs,a bit of a gut. I bought the smoke slub xxl and I absolutely love this coat. As soon as the coat arrived I put it on and got into the shower to test the waterproofness, 4-5 minutes hood up, faux off, let the water beat down, I do not have a water saver shower head by the way, not a single amount of dampness came through bone dry.
As to sizing it is pretty accurate. Although the armpits seem a bit snug. I am about 45 chest and 36 sleeve. sleeve is a tad long, but not in the way of anything, i like it like that. Expected a little more room in the armpits hence the reason I went with the xxl. Notice i said snug, I have a pretty good range of motion when active in this jacket.
Stitching around the thumbholes in the wrist gaiters is a bit weak. frayed a bit. EASY FIX.
Had this on and a stoic merino crew Snowboarding in the teens and stayed at a perfect temperature moving or just sitting on the side of the hill.