We are not talking of an FMS, I don't think that a normal not apple efb is made in that way, as far as I know it's just a certified computer, and both in the cockpit are made exactly in the same way, they don't run on different CPU, hard drives, nor software... Most of them are even running windows with the old hard drives and I think you will agree that an apple software with a solid state memory is much more reliable. Emi test has been done and succeeded and the iPad is now certified in that, I've no clue on how many times they made it because is not my job, but if and aviation authority says that is tested from my point of view it means green light, GO!