I don't own an RX100, but my dad picked one up last year before doing the Camino, rather than hauling his Canon DSLR rig, or being stuck with crappy iPhone shots. It was a great solution, and he brought back plenty of images that wouldn't have been taken otherwise, or likely would have been ugly low quality on a small-sensor camera or phone. For what you can get the original model for these days, I'd say it's definitely worthwhile, as picture quality to size ratio doesn't get much better.
Whether the new model is worth the MSRP, is another matter. If the lens is as good as claimed, if the viewfinder is usable, and if you'd use other new features like the flip-screen and wifi, then I can definitely see the new model being a winner. One thing I never much liked about the first two models was being limited to 28mm for wide-angle. If the lens is significantly improved from the 28-105, in terms of corner-to-corner sharpness, I could see it being a great hiking camera for folks who don't need ultra-wide or telephoto lenses.