Consider getting the RX100 III, it has a much faster lens
Actually nope.
The RX100M2 comes with a 28-100mm f1.8-4.9 equiv
The RX100M3 comes with a 24-70mm f1.8-2.8 equiv
As you can see : the lower f-number is EQUAL.
So you can use the RX100M2 in the dark just as well as the RX100M3, as long as you're staying at 28mm (24mm for the RX100M3).
And in bright daylight, you'll have to stop them down anyway.
The difference is, as long as there isnt too much light you can get a bit more shallow depth of field from the RX100M3. Or get better chances at snapping a picture at something else but the lowest focal length. Personally I think thats not a priority for me with a 1" compact.
The main reason I can see the change as good is that f/4.9 is probably already past the diffraction limit of the 1" sensor, so a f/2.8 upper aperture is better in this respect.
Plus, 24mm instead of 28mm at the lower end is nothing to sneeze at.
But ultimately it comes down to taste. I'd rather have more telephoto.
[...] but m43 has a very good price/ size and performance all things considered. [...]
Actually neither M43 nor APS-C sensors are any expensive anymore. Thus APS-C, with its bigger performance, has the crown when its about bang for the buck.
The only good reason to get M43 is if you want small size.
[...] To be honest, I found most m3/4 cameras not much smaller than entry level dslr cameras. [...]
Thats because they have to fit into a human beings hand.
I recently tried to pick up a Fuji X-E2 in the shop and it HURT. Because I couldnt get a good grip at all and the camera was cutting me. I couldnt hold the camera straight either, not with a single hand, I could hardly keep it holding. Now the grip of my Ricoh GRD4 isnt any better, but I can hold that camera without issues because its much lighter.
Thats because I have relatively large hands and these cameras are apparently made for asian hands... ?
So yeah, theres a limit to how small you can make cameras.