I believe the figure of 30% is the longer TBO of GE engine of the Denali (vs PT-6) and not the fuel burn. What is missed in comparison was the plentiful TBM's of variety of sizes, horse-powers,speed, and weight category. which are another family of working single engine Turbo Props.
I am not quite sure if these category of aircraft (S.E.Turbo Props) are allowed to operate as in Part-135 in USA and specially IFR at night as they maybe allowed in Europe, and would like to know for sure. If not, then their use will be limited to private and corporate owners only and not as charter service. Just curious. Thanks.