Yup, I know, it isn't a Canon review or a lens that will fit on Canon but the review is worth reading as both the reviewer and site owner are willing to experiment with new equipment, even if it means not getting the shot, e.g. from the review:Last year Michael used the Olympus E-M1 in Antarctica and missed some crucial images because he was using 4/3 lenses that did not use the Dual Phase-Contrast auto focus. By the time the lens focused, the shot was gone. This was most noticeable when shooting a whale breaching against a dark ocean background. I am convinced with the 40-150mm and 12-40mm Olympus Pro Lenses that this kind of shot won’t be missed this year when I take this gear to Antarctica.
... it is reviews like this where you find people talking about the bleeding edge of photography - included what blood was drawn!
But you've got to wonder, what would a EF 80-300/2.8 look like?
and how big would it be, etc?