The consensus seems to be that the Theilert is, to put it mildly, overengineered. Apparently a 2-stroke would have done the job of the 4-stroke Centurion. Add to that the costly teething problems the Theilert had (the problem has been fixed though).
Apart from that, the TwinStar's first delivery was delayed by 4 months - no idea what wrong but it sounded like they were having serious brainstorming sessions. Could've been over the certification for the TKS systems - all the European customers ordered it (big surprise).
Interestingly, Diamond isn't providing any real training for the DA-42 except cockpit familiarisation - I hate to say it but I predict a few 'aviate, navigate, communicate' accidents in the making. In my opinion the aircraft is close enough in performance and systems to a light jet (due to very low drag, FADEC engines, G1000 and sundry other bits) to require extensive type-specific training. However, the EASA and FAA are treating it like an automatic car - no retraining required.
Incidentally, the
first customer delivery of the TwinStar took place within the last 2 weeks. Finally!