Anyone that says a compact can't compare to a DSLR in low light, hasn't used an RX100.
In my quest to avoid constantly shelling out for the latest and greatest camera I've recently being dong some empirical testing at home with a d7000, x100, GF1 & 3 and a RX100. The subject has been my kids and the setting indoors - big windows but Scottish winter.
I have to take issue with comment above, given my scenario. There is a very clear difference between all the camera outputs and it is very easy to distinguish between their respective images - I amuse myself by blind testing in LR.
Much as it ails me, as I was a very early adopter of the RX100, there is absolutely no comparison between the images produced by a D7000 and the RX100 in their OOC state. It may that with PP you can get similar results but not straight off.
In descending order of excellence:
D7000/35mm 1.8
X100/23mm 2.0
GF1/3 with Panny 20mm 1.7
RX100 (1.8 -2.8 range)
Of note, when Using flash the results are in the same order but the d7000 and x100 are streets ahead of the others.
And of all the images the RX 100 output is way behind the others.
Just to balance the argument!
In sum, I think your best images, VFM and flexibility would come from a 4/3s like the Panny (loads available
second hand), although I find myself using my iPhone 4S more and more! And it's truly pocketable!! And there are some great apps to improve the mediocre shot.
(The GF3/14mm combo is pretty compact)