Canon S1IS telephoto lens: reviews?

Hi folks,

I just purchased the Canon S1IS. Although I find a few quirks and am
disappointed that the power supply has to be purchased separately, I am
wondering whether or not the 1.6x telephoto lens is worth the cost? Are
there any reviews of the camera with this lens? My goal is to capture
wildlife (birds, woodchucks, squirrels, etc) from a distance and I'm finding
that the native 10x optical isn't quite enough, however I don't want to
compromise the image quality by adding the telephoto if that's what will
occur.

Thanks,
Bill P