After all the hype and rave reviews, I've bit the bullet and just purchased a Sony RX100 M3 .
Thank goodness for Amazons returns policy, is all I can say. Its going back!
Despite the smaller sensor, my G15 TOTALLY smokes it in lower light.
Why? Because when shooting images using Auto ISO (my preferred choice) despite the fast lens, the Sony favours the SHUTTER SPEED for some reason, keeping the ISO higher than it need to be. Its like Sony doesn't trust its own famous "Steadyshot" image stabilisation to stop the blur.
In many of my shots taken with the G15 (and the RX100 simultaneously) the Canon camera has LOWERED the ISO, but relied on its IS to counteract the slower shutter speed.
Credit to Canons IS, it works perfectly, and it shows in my shots
With the Sony I was getting ridiculous ISO readings of 4000 in a room that wasnt really all that dim.
The same shot with the G15 had an ISO reading of 800
Go figure which images looked the nicest.
I wasn't really impressed with the images in good light either.
They just looked so "artificial " and digital.
The Canon may be slightly larger and not have the megapixels, the larger sensor, EVF or fancy revolving bits of the Sony, but what it does have is a lovely natural butter smooth image that is a joy to view on any monitor
Don't get reeled in with the overrated hype of the RX100 is my message!