Upload & Sell: Off
The WiFi based remote control should be a reason by itself. Manual focus with live view on a tablet or your smart phone is incredible. Maybe not for fast types of photography, but for landscapes, portraits and candid photography a.o. this is really more than a gimmick.
My suspicion is that the WiFi Live View video signal to your phone/tablet is relatively low resolution, perhaps similar to the 640X480 USB video feed. This resolution may be a practical limit for use of the WiFi for manual focus of Alt lenses, but will be absolutely fine for composition. You can magnify the video image with the camera, but it will still be relatively low resolution feed on a high resolution pad.
The camera LCD has about 1 mp, similar to a basic HD signal. Does you phone or pad with the 6D have equivalent or greater resolution than the camera LCD in Live View?
I would like to be proven wrong.