I imagine that the RX100 will be better in low light ( i haven't tried my xf1 yet ) and will also capture more detail
The XF-1 is a decent camera for the current price. I had two of them and sold both.
I thought the JPEG colors were good but, the images were a bit soft for my tastes.
It's not a bad camera. Built quite well but, it didn't turn me on.
Couple of ones from this week
early riser by damianmkv, on Flickr
dawn on the jetty by damianmkv, on Flickr
the terrace by damianmkv, on Flickr
the end of the day by damianmkv, on Flickr