I thought the camera shell was magnesium, as it has been in the PD150 and before that the VX1000 lines?

camera does have a magnesium frame inside.

Concerning motion artifacts : is it produces during fast panning of the cam or when you tray to catch fast movements on the set while not moving the cam ??????

You'll see artifacts when panning. The slower the cineframe, the worse it becomes. CF24 and CF25 have a great deal of artifacting, but it's not terribly unlike what film does.

Doug : so you are saying it is better than ordinary film? If so why is everybody complaining about it?