Looking at picking up either an iPad Mini 2 or an iPad Air 1 to use with my P3S. What are owners opinions on these as I'm hearing folk on some FB pages tell me that the latest versions of DJI Go are laggy running on the Mini 2? Not sure about the Air. I think it would be ok, weight and size wise as I use an Inspire 1 alloy mount at the moment anyway. Either of them I think will need to be cellular versions in order to have GPS present, am I right? For map coverage and IOC modes, Follow Me only works with cellular I believe? Any opinions welcome. Please no 'Get an iPad Mini 4, its the best' replies as I'm only looking at a £200 GBP budget so it'll be a pre-owned tablet I am after. Many thanks for any input!! Oh and curveball option could be an Nvidia Shield K1, hearing good things about those too!!??