I’m astonished by the quality I see coming out of the Sony Cybershot DSC-RX100. I used it extensively on my recent 12-day trip, especially while mountain biking where its tiny size and 240 gram weight are impossible to beat with any camera on a quality-to-size ratio basis.
That said, realizing 20 megapixels of details from the Sony RX100 is not realistic; most of the time there appear to be limitations that limit it to something closer to 12 megapixels, based on the variety of field shots I took. I don’t know the reasons— could be the lens, the JPEG compression, diffraction, etc.
Still, highly recommended, get the Sony RX100 from B&H Photo.
I deem the Sony RX100 an important camera for 2012, one which portends a wave of advances in other formats (full-frame DSLR, APS-C Micro Four Thirds, etc). The Sony 20-megapixel sensor appears to represent state of the art sensor design, given its dimensions and photosite density.
See my review of the Sony RX100 in my Guide to ALLVIEW, as well as my discussion of the Sony RX100 sensor size and its implications.
As much as I like the RX100, there is a caveat: lens performance at the medium and long end looks quite mediocre, not suprising as it is already close to being diffraction limited by the middle of the zoom range.
I would much rather have seen a 28-50mm f/1.8 - f/2.8 equivalent, with tighter control over optical performance. The sensor is clearly underserved at the medium and long end. Which for me is no big deal; most of my shooting is at the wide to medium end. But I caution prospective users to not get too excited about the zoom range.
Build quality: at the long end, some frames show asymmetric blur on one side (a report from a reader confirms the same issue with multiple samples). So a Zeiss lens design is no guarantee of quality, as both the design and assembly quality can greatly affect the actual performance.