Consider a size up - Rab Top-Out Hoody - Men's

Great top but very trim fit. I already had an understanding of Rab sizing as this isn't my first Rab top, but this seems to be an even more snug fit than I had expected. My clothing (Columbia, Marmot, Patagonia, etc.) size is usually Large if a very relaxed fitting item, otherwise XL. I ordered an XXL in this Rab top because I prefer a loser fit. I'm athletic (xc ski, rowing, hiking, gym), but not an athletic build (5' 9", 200lbs, 38" waist) but even the XXL was a bit closer fitting than I'd hoped. Not tight, but quite fitted. Even still, I liked the style and multi-purposefulness of the top so will keep it. For an athletic-fitting Rab top, the sleeves weren't as long as expected for an XXL. They fit me just fine but a taller guy with long limbs might be disappointed.

The weight of the fabric was slightly heavier than I had expected but I didn't consider that a deal-breaker.