I have Phantom 3 advanced and have been using my iphone 5s to fly but would like a bigger screen. I got a 6s yesterday but was planning on ipad mini for a while. so should I get mini2, 3, or 4? I don't need it to be ultra fast but would like to minimize lag and problems. is the 2 fast enough for latest firmware or should I just go for the ipad mini 4 ?