I wrote the following review in 2012. Since then, I have used the SONY RX100 III, IV, and V. I think the mark V is far superior to the original RX100 (reviewed here) in auto-focus speed and accuracy and in less shutter lag (faster to take a photo), yet the mark V is twice the price.
Superb image quality and usable features
I have not read the manual, but I have used the SONY DSC-RX100 for 10,000 photographs and 400 videos. The RX100 goes with me almost everywhere, including my trail running, hiking, and boating trips. The camera has become wet, but not submerged, several times. The camera has quit working because of the water on it a couple of times. I remove the battery, replace the battery, and the camera resumes operation.
PROS: The best image quality that I have seen from a camera that fits in my pocket. 1.8 at 28mm is fantastic for low-light photographs. I get photographs with the SONY RX100 that require a flash with other point-and-shoot cameras (see sunset photo taken as a passenger at 65 MPH without flash while two point-and-shot cameras used flash). However, when the zoom is engaged (29mm or greater), the ability to focus in low light is drastically reduced. I use features on this camera that I always wanted to use on other cameras, but was heretofore unsuccessful in getting them to work, or the result was unsatisfactory. Now, with the RX100, I take night, macro, and panoramic photographs. Night shots without a tripod simply amazing ISO 25,600. First camera that Panoramic mode works as I always thought it should. I could never get a panorama with the SONY HX9V or any CANON compact camera (I have owned 10). I have never missed a panoramic shot with the RX100. Superior Auto (sunset and dragonfly photographs). Shoots multiple shots quickly (6-10 fps range).
CONS: The flash does not close automatically and will not close if in Fill-flash mode. The flash seems flimsy. I hope it does not break. Having to charge the battery while it is in the camera. The cover on the camera where the charger adapter plugs in is plastic and seems cheap.