after look at all the review, posts, photos in the other thread etc, make me want to get this camera instead of the Canon S100. One thing that hold me back till now is the higher price n the size (not that compact compare to Canon S-series).
I tried the Canon S100 at Courts. Nice metal feel and small, good for quality pocket camera. But totally different feel from the X10. With X10 its feels like a mini DSLR with great control and handling, especially the manual zoom. The S100 more like a toy camera.
Found I missed the instant flash popup of the X10, the S100 needed to use menus, which takes time. Also the color balance of S100 could not set in actual color temperature, only presets and custom. On the X10, I normally set the K settings to be around 2500, which works great for fast shifting to very yellow tungsten lights. And you can test with tungsten gel and preset those and can call back quickly.
On X10, I use quite often with EF20 with tungsten gels and balancing color (tungsten flash and background tungsten) is much easier with the actual K setting function in X10.
Also the auto iSO for S100 max out at 1600, though you can set higher ISO manually. Also while it seems that S100 got good low light capability, that's only at wide angle, cos once you zoom to telephone, aperture drops to F5.0, while the X10 drop only to F2.8, so X10 lens got 1.5 stops advantage at the longer end. Made quite a lot of difference.
In short, if you want a pocketable, small camera with good quality images, Canon S100 may work for you. If you want to have something with good feel and control, with good quality images, the X100 is better, although its not as pocketable. That don't mean I won't buy a S100 to stuff into my pocket. But the X10 will be first choice for me.
And its not fair to compare the price of X10 and S100. While both have small sensors, the X10 is really in a different class from S100 (built, fast zoom, control, made in japan etc)
In the hands of someone who knows what they are doing, I believe the X10 would have great number of better images.