I think the DA42 was a great formula which would have eventually been very successful.
Total flow rate is identical to my TB20, at the same cruise speed of 140kt (11GPH) but you get a spare motor in that.
I say "eventually" because Diamond p*ssed off so many people and that was before Thielert went bust. The reliability was so poor that one needed the second engine! I know of a number of owners and almost none of them dared to fly them anywhere too far. Defeats the point of a twin, completely.
I am sure 5-10 years from now it will be a well shaken down airframe with reasonably reliable engines. Shame it will have taken that long. That is longer than most private pilots' flying career.