The problem, as always, is the price. You can get tiny screens like
that of the Dynon EFIS for around $2,000, but apparently when you
expand to large screen size, the cost goes up astronomically. It's a
bit tough to nail down exactly what one of these units costs but I'd
venture to say that $30,000 to $40,000 might cover it, maybe.

I doubt that the cost is the screen. More likely, it's the
certification. It's probably Class B $oftware, maybe Cla$$ A $oftware,
and they've probably done a bunch of user interface testing and
prototyping and requirements analysis and documentation and all kinds of
things you don't have to do for "experimental" equipment. It's lots more
expensive to do things that way than to put something together that
seems to work and looks okay to the designer. Please note this is a
generic comment, and NOT a comment on the Dynon, as I know nothing about
its development, reliability, user testing, or anything else.

Again, not a comment on Dynon, I heard that there was a PDA based
standby attitude indicator shown at AirVenture a year or two ago. If you
shook the sensor, it would lose its recollection of which way was up,
and would show erroneous information with no warning flags. The
"solution" was to turn it off for two minutes.

After all the safety, certification, and human factors I've been exposed
to, I get real leery of all avionics, and not just the experimental...

Ed Wischmeyer