I cannot speak to the DA40, having never flown one.
But, I have just completed extensive testing in a gasoline powered DA42L, and was extremely impressed. Much of the testing was engine operation in hot weather and adverse conditions, and it all went very well. It is a delightful aircraft with lots of oomph. The market will be well served by this version of the aircraft.
A few things were a bit unusual to an old Cessna Piper driver, but I opened my mind to a new way of doing things, and adapted well...
We were also given a diesel version to fly, which neither of us had previously flown, and I quite liked it as well. What a shame those engines have a challenged future, as they make a pleasingly simple powerplant for pilots to enjoy.
I can highly recommend the aircraft
Pilot DAR