AI Noct: 480g, AIS Noct: 465g, so a little lighter but not by much. The build is different (most AI and AIS are mechanically different in spite of the similar appearance) but I wouldn't say one is substantially better than the other...
As for the focus throw, I have the AI 55/1.2 which has a similar form factor and long focus throw as the AI Noct, I find the focus throw is a bit too long, very slow to focus from infinity to close. I think 140° of the AIS Noct should be about right (although I agree that many other AIS lenses have too short focus throw)