The low-down: Canon has broken with the top-quality compact mob with the S100, increasing the megapixel count to 12 and boosting the zoom range to 5X (24mm-120mm film equivalent). After Panasonic startled the world with the LX3, with its modest zoom and 10-megapixel sensor, the other brands followed suit.
The S100 no longer conforms but continues to be a serious camera with full manual (as well as automatic) controls and the ability to capture RAW. It is small and robustly made. The function ring around the lens can be programmed to control exposure compensation, white balance, ISO etc, one function at a time. There is GPS and an HDR (high dynamic range) function, which seems to take a bracket of shots and then not be able to align them. Best avoided.
Like: The image quality is outstanding. At ISO 400 there is little evidence of noise and no noise-reduction effects at all. Resolved detail is impressive, so the boost to 12 megapixels doesn't seem to have consequences for picture quality.
Dislike: The battery goes flat very quickly if you forget to turn off the GPS function. A warning pops up on the screen to advise that GPS continues to drain the battery even when the camera is off. Take care. Unfortunately, the camera's Getting Started manual is absolutely useless.
Verdict: This is an outstanding compact camera. It fits easily in a pocket, yet feels rugged enough to stand a little careless handling. The control ring around the lens is most useful for instant exposure compensation - every camera should have it. With prices in Australia almost the same as in the US, this is great value for money. Highly recommended.