Had a S100 then sold it to buy a XF1. Is it better? Not sure.... Both are pretty damn good. Only quirk of the XF1 is that it tends to smudge green colors on a pixel level. Control wise I like the XF1's manual zoom and E-Fn button is damn convenient... Plus it looks so damn nice!
you can check out the image comparisons at dpreview or imaging resource.
in terms of image quality IMHO the XF1 is slightly better than S100 and LX7 but not as good as RX100.
i reviewed it on my blog late last year. check it out if you're interested: Fujifilm XF1: Review | pixelogist.me (not sure if i shared this here earlier!)
but i really didnt like the feel of it. image quality was very good, just like on the X10, i'd say... but didnt have that premium feel at all. i didnt love the design either. get the X20 if you can afford the extra cost