I flew the new Diamond DA50RG a few days ago - OMG - I just love my Commander even more.
The DA50 is nice and new, has the 300HP (270HP MCP) Diesel we all want, but is to heavy with 4400lbs and has too small tanks with only 50USG so mediocre performance. No match for the 114TC in speed, range, climb and landing performance. Very stable in flight though, but that is not enough.
If somebody would install the CD-300 engine in a Commander - yes that could be close to perfect, but it is 100lbs too heavy.