In the past few years, one (supposedly) successful flight training
school dumped their Cessna fleet for Diamonds.

http://www.eaa-fly.com/Training/Training.html

I believe they do not have any aircraft that with standard
instrumentation. Regardless, the conversation turns quickly to
"Is this a good way to go about training for your PPL?"

Since most rentals, especially lower priced ones, are Cessna 15x/17x,
the transition (backwards so to speak) would appear to be an issue. My
expectation is that the majority of newbies to flying look forward to
curbing not inflating costs and that they will need to be Cessna (std
gauging) prepared not glass panel prepared..

Comments appreciated.