Originally Posted by
GrumpyDiver
Kim, I own the older "D" version of the 80-400mm lens as well as the G version of the 70-200mm.
The difference you have noted is definitely there in these lenses. The 70-200mm is a internally focusing (and zooming) lens so the amount of mass that one has to move when zooming is far less than on the 80-400mm, so the force to do so is relatively small. The 70-200mm lens does not get any longer (or shorter) when zooming, where as the 80-400mm is noticeably so. The 70-200mm lens only zooms 2.9x while the 80-400mm zooms 5x.
Zooming the 80-400mm (and the same can be said about my wife's 150-500mm Sigma) takes a lot of force when compared to the 70-200mm. It's just the different approaches used in the design of the lenses; the 80-400mm is a consumer lens whereas the 70-200mm is a pro lens.
I cannot comment on the most recent 80-400mm G and 70-200mm E lenses, as I have not shot either.