[Twiggs]

I have been using this lens for last year with a Fuji S3 Pro and gives pretty good results. If you are using a Canon and are looking at using it mostly as a telephoto lens then if you can afford it keep to a Canon lens. I do find this lens a bit slow for working on surfing or wildlife.
Also noticed if using this lens, set your WB don't work with it on auto WB. Huge difference in colour.

Hope this is of some help