One thing you will notice with the 9900 (and I would bet the 7900 also) is that there is no more shake and bake.
As has already been mentioned, 7800, 98880 both did this to some degree. The 9900 seems to have the motion
issue figured out, at least when in the stand. The 7900 is close to the same weight, of course not as wide, but I
would assume it would also have much less of the motion issues.
Paul