At the time I bought the E version in late 2015 I was using a copy of the G purchased new in 2013; my previous one (from 2008) was damaged (though still usable). The two year-old copy of the G lens was quite comparable with a new one. The zoom mechanism in the G was never that smooth or even resistance to begin with. Personally I think the mechanical characteristics of a lens should remain unchanged for at least 10 years of use without service especially if a lens is intended for professional use. The E version seems more ruggedly built, the zoom mechanism works better (more even tension) and Nikon also said that the lens can withstand impacts from the side better than the earlier version.