As I gave my Panasonic to my daughter, I just bought the S100. I'm very impressed with the controls and the handling. Battery life is not so great, I'll surely have to buy a spare. I like the fact that I can move the focusing frame around the image and the customizing options. One of the down sides is that, although the camera detects rotation, it doesn't have an electronic level. Image quality is fair for such a tiny sensor, I didn't really expect more. I've pondered getting a G1X, but the price is more than double and the main reason for having another camera beside my 50D, a pocketable camera that can be with me all the time, is not achieved with the G1X. The best thing about the S100, for me, is the handling solution that is very intuitive and fast, allowing to change many parameters without having to go deep into menues. The C ( custom mode) it's very useful in this respect, with a little thought, I made the camera to be ready for my usual use instantly, and all the major controls at my fingertips with very good buttons and rings.
Canon PowerShot S100
Canon 50D , SIGMA 10-20 f3.5 ,Canon EF 24-105 L IS USM, Canon EF 100/2.8 macro Canon EF 50/1.4 ,Canon EF 85 f1.8,Canon EF-S17-85 4-5.6 Old Tamron 28-300 inherited from my Canon Rebel G film camera