Has 30+ years of SLR/camera experience.
Extremely well built, good zoom range, removeable rotating tripod collar
Heavy, not really usable below f6.3
This is a very useful lens for video work and still photography as long as you don't mind the size and weight and are willing to use it at apertures from f6.3 to f11. Wide open it's pretty bad.
The zoom and focus rings operate very smoothly, which works in favor of the lens for video useage. I use mine on a Panasonic Lumix GH1 camera, on which it becomes effectively a 170-600mm lens. It's great for wildlife and birds as long as you have enough light. When shooting video the shutter speed is best set to 1/30 to 1/60 second in most cases. At those settings, the small apertures become less of an issue. I mount the lens on a Kirk King Cobra gimbal head and use a heavy duty Gitzo tripod.