If I told you the number of hours I've spent looking and calling for the perfect Android tablet for use in flying you wouldn't believe me. (Edit: so much that I've more confusion then when first started looking, inquires just created more questions and less answers)
Less then the perfect tablet is acceptable .
I like the Samsung 8.4 Pro but WiFi and Cellular together are not available and the GPS is not stand alone but requires a WiFi/Internet connection. WiFi is just not that wide spread that I've found on the ground, is it more available at altitude but below say 1000 ft agl?
The geek in me also likes bells, whistles, buttons and lots of sensors for available apps to exploit.
The iPad Mini seems popular, though not a fan of proprietary.
What are you using?
Ken