Depending on what they’re shooting, the 800mm could certainly be …
Depending on what they’re shooting, the 800mm could certainly be overkill. I’m not knocking the lens, it’s a very sweet piece of glass, but it will only really be required in very specific shooting conditions.
I’m amazed by incredibly light it is when you compare it to other Canon 600mm+ lenses. If it weren’t bulky (as if a non-bulky 800mm lens is possible), it would almost be hand-holdable (note the “almost”). A lens of that size under 10 lbs? Pretty sweet. Compare that to the 600 f/4 IS @ around 11 lbs, and the gigantic monster that is the 1200mm f/5.6 @ a massive 36 or so lbs…