Yes three accidents and maybe a few more over the last 20 years, indeed nothing is perfect, how many accident if consumer electronic was involved in control of your aircraft?
point I was trying to make there is no new business model where the X50 will be more rational or cost effective because I bring my $500 tablet onboard.
Just as an annex the A350 lets you indeed plug in a portable device into the system of the aircraft and upload flight plan that you prepared offline (supposedly in your hotel room)
The device is also an Airbus device that looks like one of the first generation Toshiba laptop computer, brick size, 2 inch thick and probably fire walled in hardware not software.