The Bad Elf external GPS receiver will connect, with Bluetooth, up to six devices so no snags if you do go down that route. My preference would be to pay out the extra squids and go for the cellular version because you then have an option up your sleeve, even if you don't ever stick a sim card in it. I've got a normal iPad (with cellular) but use the Bad Elf anyway because then I never lose the GPS input and I find it works well in all aircraft environments i.e. big, small, metal, wood and plastic.