First ride, middle seventies temperature. Removed the liner and found the jacket to be very comfortable with lots of air flow. Low sixties today so I put the liner back and went for a two hour ride. For me, I don't think it will be good below 55 degrees or so unless I wear another layer above the waist. I could definitely feel the cool air through the jacket. Sizing runs big so rather than a medium I ordered a small, as suggested by the helpful guy at Revzilla. Nice, snug fit, just what I wanted. I'm very pleased with the jacket so far. A little concerned about the back pad on a warm day, I'll report when I know more.