I used the CamRanger last week for the first time on a 5d2 & 5d3 while on location and it was flawless - 64gb and not a single problem. I used an original ipad which cant see a raw file so I had to shoot Raw + small JPG which was no big deal - I just trashed the jpgs once the card was d-loaded when back at my studio. I never had to stop and show anyone anything on the back of the camera - I was able to just keep on shooting while they were busy tagging the files they liked. The client mode is great and kept my client from messing with any camera settings.
The only complaint I have is finding a good way to mount it and run the cord to keep everything tight and compact as possible. TetherTools give a free stick on Mighty Mount which was a bit gooey after a long day of shooting.
The ability to connect multiple iPads would be a welcome update if thats possible.