A great lightweight jacket, good for chilly temps and wind and stylish to boot. Works fine for VERY light/brief rain, but anything beyond that it's no good at keeping out moisture. The fit is very snug, I'm 6' tall, 168 lbs and wear a men's medium 99% of the time. Got a medium in this jacket and it is super tight. Even the wrist openings are weirdly small. (I have small wrists, and it's a bit of work getting my hands through.)
Overall, though, it's a dandy jacket.
This is a race-fit jacket of very lightweight, barely-elastic material. Either it fits you or it doesn't. It does fit me. The cut is pretty good (for race cut jackets) and does not flap, although the venting panels near the underarms/lower lats create a bit of extra material. Sportful is accurate in the description - it might add 5-7 degrees of comfort from cold or wind. And that's really nice to have when you want it, especially when it weights nothing and doesn't even fill up a back jersey pocket.
I rated the jacket at 4 stars becasue I haven't ridden in it yet. My main concern was the fit after reading the online reviews about it running very small. I'm 6'1", 160 lbs and 64 years old with 39.5" chest. I ordered the X-Large and it turned out to be too big and returned it for a large. The Large is a comfortably snug fit around the waist and chest when wearing a long sleeve jersey and undershirt. Sleeves length is ok (longer is always better in my opinion) and room inside for a thin set of elboe pads. I'll report back with how it holds up after getting some miles on it.