iPad Air 2
I use an iPad Air 2 bubble-mounted with a standard suction type mount. I find the bigger screen really helpful and like md600 driver find the weather update on Runway HD really useful. The Air is much lighter than the standard iPad so other than on startup doesn't vbrate too much.
It is full of strong magnets though so don't mount it to close too the compass!
I also carry a cigarette lighter charger, which works fine and means battery life is not an issue. I also use my iPhone 6S (the small one) as a backup GPS again running Runway HD, which is a bit small but fine as a backup.
I won't fly without them these days.