I heard my name
Canon are excellent and easy to use but battery life is nowhere near the Sony RX100 or the Panasonic LX7.
When you shoot stills canon S get two dives with one battery RX100/LX7 4+. In video canon does not get to 2 dives you get 3/4 from the RX/LX depending on shooting style.
So the choice is narrowed down to RX100 or LX7.
In general terms if you shoot mostly pictures and occasional video I would go for the RX100, this camera offers more lens choices in terms of fisheye and the still benefit from the larger sensor a great deal.
If you shoot mostly video with occasional stills then get an LX7, the camera beats the Sony hands down on macro both video and still however the widest you can get is 100 degrees with an Inon UWL-H100. There are no fisheye or semifisheye options for the LX7 as the camera lens is simply too big.
A few video comparisons:
LX7
[youtubehq]JWdwsPdBxqY[/youtubehq]
RX100
[youtubehq]DuCMkUyYiDE[/youtubehq]
For stills look on nauticam smugmug (there are many excellent RX100 pictures but those are taken with the same diopters and wet lenses)
NA-RX100 test @ Anilao July-2012 - Nauticam Photo Gallery's Photos
NA-LX7 test @ PG Oct-2012 - Nauticam Photo Gallery's Photos
The RX100 photos are cropped this camera needs +12 or more to get to real macro
I have extensive information and tests on my blog
Interceptor121 Underwater Video | Tip & Tricks for Digital Compact Cameras Users look into the archives for the RX100