Some compare this objective 70-300mm Canon L series, sorry, but it is not comparable. The autofocus reacts much better (no unnecessary return without having found the point), faster and more quietly. The weight of the L series model is more important, but paradoxically allows for greater stability. The stabilizer is also much more discreet. This "L series" gives a much better and more solid feel. Well obviously, it takes the triple price level, everything is paid ...
To report a pathetic pettiness and amazing from Canon: no sun visor, a "piece of plastic" indispensable and yet not necessarily easy to find (there was nothing on Amazon when I ordered) .
Lightweight packaging, mine was warm considering the condition of the packaging of the lens: large lateral impact, fortunately without consequence for the telephoto that works perfectly.