I'm not much of a techie when it comes to photography, so can't comment much on that, but I can tell you the body is robust.
I took some shots inside an old hotel last weekend. I made a wrong step on the stairs while holding the RX100 with lens and flash out. It took a hard fall from 3 or 4 steps and landed on the lens. It looked like it was stuck, so after I turned the power off and pushing the lens gently back. After turning the power on I tested it: no harm done... for the camera that is.
It's a great pocketcamera. I do feel the jpegs straight out of the camera lack detail, especially at higher ISO settings. The RAW files are great for such a small camera. The controls need getting used to coming from a dSLR, but the Fn button can be programmed for most of the important functions. Battery life is acceptable. I do find the startup time a bit slow, but maybe I'm spoiled by using a dSLR. I do remember my old Canon Ixus and Fuji FinePix compacts starting faster.
Using your finger to bounce the flash is handy indoors btw.