I don't believe them to be more dangerous then any other saw, however every saw carries risk, I was more referring to your comment on their light weight, You said rotating mass but they're overall mass is so light that they're very easily controllable.
Anyway since the vibration doesn't seem to be teeth rattling on any of the aforementioned saws, and do to it's limited use I don't think weight will be life or death, heck whats 1kg anyways, (that was a joke after 12 hours 1kg is a slap in the face). I think I'm going with the 9010 if I can get it since it's not in production for the north american market, if I can't I'll go with the 390xp unless the 7910 is $275 or more cheaper.