Originally posted by philbaum Fundamental question: "backup" for what? Probably makes a big difference if you need a backup for your professional work, or if you need a backup as an enthusiast or for backup on a vacation trip.
I'm interested in the RX100 also, but of the comparison photos i've seen, the RX100 clearly can't compete with the pixel peeping detail from an APS sensor of the K01 or similar, which is much larger than the 1" sensor of the RX100. But any camera with an APS sensor with a lens, will not be as compact as the RX100.
I fully agree with your comment that surrounds new cameras, the buying frenzy seems to be in full swing on the Rx100. I'm tempted myself as I get a bit tired of lugging around my aps K5 camera and lenses, for casual shooting when an RX100 or similar would do just fine.
The backup camera would be used strictly for personal work--but serious personal work, if you know what I mean. Up until now, I have never carried a second camera, and fortunately, I have not needed one, but it might be nice to have one just in case. Stuff happens.
Right now, my guess is that when people start looking carefully at the files from the RX100, they will be found to be inferior to a good APS-C camera, although superior to any of the current generation of pocketable cameras. You get a lot in a very small package, but there are limits.
Rob