To begin with, you need a 32-GB Nexus 7, which would have the required storage to off-load photos (in the form of 20MB raw files) from the Sony RX-100. If you're traveling in Europe where data SIMs are cheap, you might want to consider the HSPA version of the Nexus 7.
In addition, you'll need the following pieces of hardware and software:
- OTG Cable
- Memory Card Reader (this one does CF cards so you can use it for your DSLR as well!)
- Nexus Media Importer
- PhotoMate Pro
- PhotoMate Pro Raw extension
Overall, I've been very impressed with the results. Imports are relatively fast, even for hundreds of RAW 20MB shots. PhotoMate does a great job with RAW, and has a built in JPG converter that lets you post to your favorite social network (Facebook, etc) using the built-in Gallery App after the JPG conversion. (For whatever reason, PhotoMate's direct sharing feature is broken and doesn't work)
Adjusting the exposure, cropping, tweaking the white balance are all easy and usable on the Nexus 7 with its quad-core processor. My biggest complaint is that displaying the results of your adjustments is slow, but these are on RX-100 raw files. With a lesser camera you shouldn't have any problems. The only major feature that's available in Lightroom but not PhotoMate is ND grad filters. I basically relegated features that needed such work to the desktop with Lightroom for when I got home after the trip.
The availability of these apps and these features have turned the Nexus 7 from an unnecessary luxury on trips to an absolute necessity. Not only is the Nexus 7 now a suitable posting tool for my non-wifi enabled cameras, the Nexus 7 is also a reasonable backup for the photos in case the camera got stolen or something bad happens to SD Card! Add in the ability to run a data SIM and the Nexus 7 would be even more useful.
I never thought I'd say this, but for my next Europe trip I can see myself ditching the Kindle and just bringing a HSPA+ enabled Nexus 7 along with the above kit. Needless to say, that means I'll look forward to the next iteration of the Nexus 7.