I don't believe the Silver Vista has side windows. And the movement of the train alone creates enough wind to blow rain and cold air into the car. Despite being dressed reasonably warmly I was very uncomfortable in the Silver Vista on a blustery day. The problem is not so much cold and rain but the wind. I have not ridden the Knight Sky, but if it has side windows to go with the glass roof, that is a nice combination. My personal favorite remains the Alamosa with its rear platform to view the track.
JBWX