Overall, not bad. It's shaped as if for cold weather, but the material is not super thick. The baffled/quilted chest area does seem a bit thicker, which is nice.
My primary issue is that I ordered a Medium, which is usually the right size for me for Tentree, if a touch relaxed with room to move. Pulling this on, I somehow popped a stitch in the arm. My girlfriend immediately mentioned this not giving an impression of quality, and I really agree. Secondly, this is a hoodie... but it has no pockets. For minimalism it's probably fine, but if it's your outermost layer you may want somewhere to tuck your hands every now and again - no luck. Third issue is that the mobility is a bit lacking. If I hold my arms in front of me, this is a bit restrictive... so maybe if you are layering for the cold it MIGHT be an adequate mid-layer, but if you need to... I don't know, ride a bike, load a van, do anything with your body, it might just keep popping stitches. I don't know. Lastly, the quilting on the chest does extend fully down the arms. Where the chest lays flat, the arms are designed to bunch up a bit, so there's a little visual dissonance there. Bit of a bummer for $100... but I do like Tentree, and I do like the quilted/flat distinction visually, and the material is comfortable. For future versions, please make the hood larger, consider pockets, and test the range of motion.