My wife and I just ordered Montbell Thermawrap vests, having had great experience with the hooded parka (only 13 oz in L and super warm), but have found the sizing all over the place. We got a S, M, L in case my wife was between sizes – what I didn't expect was the size L not to fit me. In any case, all sizes are snug in the waist – we both have a slim athletic build – my wife is a size 8 – the vest is supposed to be unisex, but while the small fit my wife, the waist was tight, so she sized up to a medium. I had the same experience – I'm 6 ft 185 lbs 42 in chest, and I should be a large, but while the vest fit me overall, the waist was way too snug for active use. I have a 34-35 waist and it should have fit me.
What I wanted to ask is – if I size up to an XL so that the waist is not too tight, will the rest of the vest be too large?
I think these must have been adapted from Japanese sizes.
We plan to wear these under layers (we bought the parkas one size up because we wear them over layers, shell and all, during stops and in camp).

