Both the material and the fit are more like a slightly thicker thermal jersey than a jacket. Temperature-wise it's good down to the low 50s, maybe high 40s. Decent wind resistance and a little bit of insulation. But that's about the limit of usefulness for this "jacket" because there is absolutely no room to layer--an XL fits tighter with nothing underneath than my L thermal jerseys from other brands. Given Gore's reputation as true-to-size this one is weirdly Italian-esque. I'd still give it 4 stars since you can just size up, except for one other significant issue--the collar is uncomfortably tight when zipped all the way up, and if you zip it down a few inches to give your neck breathing room, the collar is too stiff and the zipper ends up attacking your neck. Overall I ended up keeping it at 50% off, but I wouldn't recommend it to others.
The Spinshift Thermo jacket is my go to when riding in temps in the 30's. Worn over a base layer and thermal jersey, I can enjoy riding while staying warm. The slim fit provides a good seal against the weather. At 6'1" and 175 lbs, the large fits me fine.
With a turtleneck underneath it kept me warm riding in 30 degree weather.
