Well lets see how to answer this....
As you know with any electronics -- some are good and some go pooy.. TVs, DVD palyers etc..
Same with car electronics -- but coming from a person (me) who does Reliability on Optics and Electronics I can tell you they are 1,000,000% better today than even as little as a few years ago. So yes with more trinkets comes more upkeep but I would be more worried about things like seals/gaskets, hinges and mechanical failures.
The HUD has been around for many many years now -- I had it on my 99 Vette (it was way better on my vette but..that is another story
) and things like the auto volume also have been around for a while..
now going on the TapShift® -- with the electroinc throttle control -- I would assume that the Tap will last as long as you do not "pound" on it, I think it will last as long as the vehicle.
In short
-- I would not worry about the gadgets - they will last.