i read a review on that lens (70-300 do ) and it was slated , particularly due to its L lens price tag without any of the quality…the 100-300 L is almost exactly the same price and is far superior . i think a second hand one of them would be a much better option
Unfortunately I don’t have the lens you’re looking for but I was using it for a short time some years ago. It was a rather expensive but not very good lens, images were very soft and mushy with very bad detail (and this was not fault of the camera used or the photographer). The only positive thing about the lens was the weight.