Technically considered, the Sony has a smooth twice as large as the sensor surface (already not low) sensor surface of the Fuji X10. The area is almost three times as large as that of a Canon S100 (should be the same as the S95), but only about a third as large as that of an APS-C sensor. It is amazing how the technology evolves: bring my Canon EOS 40D from 2008 "only" 10 MP on a APS-C sensor, the RX100, however, twice as many (20 MP) on one-third of this area. Power mathematically factor 6 without - to anticipate it right - noise performance and attention to detail including suffering.
The sensationally good noise performance at high detail is then actually a real highlight of this camera. Up to ISO 800 without any problem, evident namely in ISO 1600 have an (at least at 100% view) clearly visible grain, but the attention to detail is very high. Even at ISO 3200 is changing only marginally, and even ISO 6400 can still be used! Subjectively, the RX100 is thus at least on par with the X10 (which roughly equally good results, but in the 6 MP EXR mode, achieved), the Sony NEX-5N (in particular this is amazing because it is still relatively new and for their "only" 16 MP has nevertheless an APS-C sensor is available) and the Canon 40D (at least until ISO 1600, about the 40D almost useless). The Canon S95 falls next to this quartet from very clear, here are useful results really only possible to ISO 800 (with pixel binning, but this goes to 2.5 MP reduced resolution course at the S95 more, but this mode I consider outside the competition).
The 20 MP of the RX100 are therefore (both mathematically and by the practice) justified and thus offer enormous scope for Crops and large format includes prints. Nevertheless, I like not imagine what potential this camera with only 10-12 MP would ... I believe that would be the (yet) been better approach because massive Crops I'm at least very rarely, and A3 includes prints I have made Canon EOS 10D without these details could be missed - even by 6 MP images of my - now retired. The reducible to 10 MP image size of the RX100 is not an option, because in this mode, no pixel binning is made, but the 20 MP only be downscaled.
Well, you may just not have it all ...
Compared with the direct rival Fuji X10 is noticeable that there are not so many function exclusions far: Yes, in the RX100 can I select a AF point manually without turning off the face detection. Yes, the RX100 can Program-Shift despite auto ISO. Yes, she also writes RAW files in all positions of the selector dial, as far as I could find so far (except for the movies, of course). And so on. Of course the Sony is not perfect: For example, I can not photograph during movie recording shoot (although the principle is to be possible) and just do not know why (probably because I have set as the output format RAW + JPEG ?!). The operation of the RX100 is still a total no-frills and significantly less "diva-like" than the X10. Anyone familiar with the Sony World already, will anyway have no problems.
By contrast, the X10 holds the better "grip"; you happens to have a bit more material in hand, everything is less delicate than the Sony. There are more hardware buttons for key functions available, which is often advantageous. Genial in the X10 is also the mechanical zoom ring simultaneously on / off switch. Fast can hardly be ready to fire a compact. The RX100 is here conventional: press on / off button, wait until the lens is extended, change focal length by motor; everything a bit slow. The - to smooth for my taste - lens ring is there more of a gimmick than real value, I use him as good as not.
The X10 also scores with its long end significantly (1.5 stops) better light intensity.
The RX100 is then subjectively again when shooting a little faster (AF, shutter lag) as the X10, though there are nuances. The disadvantage I find that between "shutter button halfway" and "pressed all the" little room is; it happened to me many times before that I took the photo, although I wanted to examine only times only AF and exposure.
One oddity that maybe only applies to my copy: It is to me so far not succeeded in using the supplied charging equipment to charge the battery in the camera. The USB port of a PC, the camera is detected correctly, however. The relevant menu item ("USB power" or so) is also enabled. The charging indicator light will remain despite everything out (and the battery is actually not loaded), whether at the PC USB port, the included USB power adapter or other USB power adapter. But no matter, I find this kind of battery charging anyway bad and always invite my batteries with a Pixo C2 + outside the camera, so it does not bother me ultimately.
Time for a summary of the pros and cons:
++ Excellent image quality (natural colors, enormous wealth of details).
++ Excellent noise performance, especially for a compact.
++ Uncomplicated handling, adaptability of the controls.
++ High-quality finish.
+ Dimensions (only one plus for the pretty expansive depth).
+ Clearly structured menu.
+ Fewer feature exclusions (compared to the X10).
+/- Battery life (much better than the X10, but there is for the X10 unbeatable favorable third-party batteries).
- Relatively faint at the long end (but F4.9 is still better than for example F5.9 at S95).
- For the size heavy.
- A little handy case (where there is a remedy => Google search for "Richard Franiec").
- Insufficient clearance between shutter button halfway / fully depressed.
- Battery-charging in the camera. (In this price range an external charger should be a matter of course.)
- Complete German manual (still) unavailable.
- RAW support in Lightroom or DxO Optics Pro (yet) available.
That's enough for a minimum of 4.5 stars, especially as some disadvantages will do sooner or later. Rounded in favor of the candidate, the then 5 stars.
What do I do now? The RX100 is really my "new S95." I treat myself beyond the luxury not to have to decide, including the X10 (which is now "grown to love" me despite their quirks) to keep. The NEX-5N and the 40D equipment for "special operations" remain anyway. So I will indeed continue to have the 'spoiled for choice', but each camera has its special qualities and therefore justified. ;-)
Pocket Tip (for the belt): The original Sony LCS-CSQ (the RX100 fits quite precisely, but itself remains in the pocket no more room for a spare battery), or even better, the Lowepro Rezo 30 (the RX100 fits with some air , then go forward to the main compartment even spare battery and memory card easily in).
Availability: Strange that the RX100 here at Amazon just today (as at 31.07.2012) is available, but apparently Sony has underestimated the demand. In Sony online store (that I bought) or stationary dealers she was to get course for a while now.