Summary: I willbe using the lens hood on my Canon EF 75-33mm zoom lens. There is a lot more hood than what I have on my 28-80mm and ef-s 18-55mm lneses, but when I go to the wide angle setting, I find that I am checking for vignetting. I feel that the corners should be trimmed a bit to avoid this.
Summary: I use all the time - really helps with contrast and preventing flare; and I can tell the difference in image quality - better quality with the use of the hood. Con - not too bulky but takes up more space in camera bag than I wanted to give up.
Pros: Easy to Use, Good Lens Protection, Improves Function, Lightweight
Summary: Canon charges a lot for a piece of molded plastic that might cost them fifty cents to make. Seems like a less expensive equivalent form a third party supplier would do as well. Reverses so it stores right on the lens. If you use a Canon lens bag, the lens & hood will fit.
Summary: I bought the ET-60 lens hood for the 75->300 mm kit zoom lens bundled with the Canon Rebel XT I purchased about two years ago. Of the several lenses I have purchased for this camera, this is the only one where I get inconsistant results. The main problem I seem to have is that the light meter seems to think there is more light available than exists and results in under-exposed pictures. This happens more often at the 300mm end of zooming.