The AF behaves differently, wether its a motor change which you wouldn't know about or not it does behave differently. I have used all these lenses including the FE versions which you haven't so you don't really know the differences. Youre basing your comparison against the DSLR version on a DSLR camera. 1) So glad we cleared up that it does have weather sealing 2) What about it? Id rather have the fastest and quietest video AF lens, the 55mm and that I can buy with my £650 saving 4) Maybe just you then and people who like a slower approach or lots of video Hey, it works, AF is fast, accurate, silent and its cheap with arguably better optics.