I'm a recreational cyclist and I don't usually go out if its below 35F. This jacket works on my coldest days. When it gets over 55 it has to come off or get at least get completely unzipped. I can stuff it in my jersey pockets, but thanks to the insulation its pretty bulky as ball. So its good for days that are going to stay cold, if you call 35-50 cold. It might work for colder days than that, but I couldn't say. Its been so warm here (Northern CA) this winter that I really haven't used it that much. The big back pocket is good for putting food in for on the bike eating, and for your balaclava or whatever you take off when you warm up a bit. The fit is great. It doesn't flap around like my old jacket. I got a small rather than a medium because I wanted a tight fit. Its long enough in the back and the arms (I'm 5'11 and thin) and very comfortable with a nice high collar to keep out the wind
I am sorry to say that I have yet to ride in this jacket as old man winter still has a strangle hold on us New Englanders. The jacket does appear to be of excellent quality and I promise to update this review upon getting a few rides under my coat.