I have not yet used my new 50-250 Z lens as much as some of you. I did do some tests of my nice little Canon 70-300 on the Z50 (Fringer adapter) to compare it with my Nikon DX 70-300 and was impressed with the Canon version. But then I shot some of the same subjects with the new Z 50-250 and saw the light! While all three lenses did quite well the Z lens beat them all on the subjects I was working with that day. More testing with different subjects under different conditions are needed of course but so far I have to give this 50-250 high marks just as others have.