So I got a G1X to replace my S100 with a broken screen (which still works however). I'm going to return it however as I'm not impressed.
It's a neat camera in a lot of ways, a real chunky monkey. Really solid and feels good in the hands. I like best that it has a hot shoe and an articulating screen. However for the price it doesn't seem to give pictures much better than my S100. I'm not a pixel peeper, and the larger sensor should surely be doing better, but in real world shooting I'm seeing similar quality in LightRoom. Which either speaks to the quality of the S100, or to the G1X, or to me, don't know. Also I don't like having a lens cap, and to protect the lens I have to get a too expensive adaptor which will pop the lens out even more.
However the camera isn't that much fun. It's almost the same size as the Fuji X100 which I have, and the Fuji takes way better pictures and is a lot more fun to use. The G1X is more versatile (zoom), but it's safe, comfortable, and boring. All for $800. My biggest complaint however is the size, it won't fit in the SnapR bag like the G12 does, it takes the Snap35 bag like the FujiX100. So it's not really a compact camera anymore but a midsize. And if I'm taking a midsize camera, I expect better pictures for it.