I use the $50 fire 7... works fine with a p3s and DJI Go or Litchi. Just a bit of video lag at times but nothing I can't work around for now. I'm working hard to learn litchi so it can do the flying and videography for me. Will eventually get either a Nexus 7 2013 or an Nvidia Shield tab - I want something brighter, and with HDMI out.
Do you have location services turned on? I ask because I've noticed that mine will show some really goofy numbers for the distance from home point. I got out for a very short flight this evening at a spot 3-4 miles from my house. I noticed that it said I was 19K+ feet from my home point. I can only assume it kept that info from when I flew at my house the night before. I did NOT test RTH!
.... I guess I need to learn to ignore the distance from home point numbers.