Ive been riding my mtn bike with this jacket for about a week now. i have worn it when it is drizzling, not raining sunny and cool and in a steady rain shower. It is waterproof so you will have a slight clammy feeling wearing this while exerting some cardio effort. It is not even close to as bad as a full on heavy raincoat. The amazing thing is that once you start a decent or have a wind the material is breathable just enough to dry things out inside. This is as close to perfect rain/breathable lightweight protection Ive used yet. I can't speak to durability yet, but so far it has been stuck by thorns and they didn't rip through the fabric. Seems pretty good for as light as it is. Lightweight. Fits into itself and stuffs into the backpacker of my bibs or bike jersey......perfect. Fit. Im 6'3" tall 200 lbs more slim than broad and bought an XL. The fit is roomy, but good. the Large i tried also fit, but was more athletic slim. Probably could go either way, but I was going to use this for more than just biking.