In looking over the iPad specs (http://www.apple.com/ipad/specs/), one thing that stood out to me was that the iPad is rated for 10,000 feet only. Since the iPad does not have rotating media hard drive, I strongly suspect that this is spec is there because of thermal issues and should be heeded.

As air gets thinner, its ability to carry away heat also decreases. According to many published reports, the iPad is fairly marginal when it comes to thermal design. There have been many complaints about the iPad over-heating and shutting down when exposed to direct sunlight, even at sea level. This problem will get worse when you are flying at 8,000 ft cabin altitude in your IV-P and a lot worse when you are at 14,500 in your Legacy.

If you are planning to use the iPad to reduce paper in your cockpit, at least make sure that you have paper backup handy.

Regards,

Hamid