If it helps someone with there choice: I also bought an Android next to my Apple stuff for the time remaining until the iOS app arrived. My - non-technical - findings:
Samsung Galaxy Tab S 8.4 has a great screen in daylight although sun cover might be better, feels very well balanced with the remote controller, battery runs down quicker than both iPad's but there might be something with the DJI app on Android and battery usage as I read about someone else having the same strange thing where overnight a more than 60% battery was drained with only DJI App "active" and tablet soft-off (again, non-technical finding)
iPad Mini2, also great screen with little less sun "issue" than the Galaxy Tab S, same good balance as the Galaxy Tab S
Ipad
Air 2, perfect screen/ user controls etc, crappy balance with the remote controller as it's just to heavy compared to the others
iPhone 6+, just a little to small for my taste but maybe I'm getting to old ;-)
Video works flawless on all of the above, not sure what "better graphics handling" would mean in this respect or perhaps all of the above have just good graphics handling from a DJI App pov. iOS has the simulator option but perhaps that's more for me at the moment now as a novice "pilot"